LIVEAnimals
1/2 ton status
Well Larry I'm sold 
CK5
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Anyone have an 8.1L in your Blazer?
- Thread starter colbystephens
- Start date
y5mgisi
1 ton status
He is good. But its just him doing the talking. The 8.1 sells itself i think.
I think the simplest answer is the engine package that you can afford And is the easiest to get. If you get a 6.0 easier to find locally or a good deal in a 8.1, then it would seem that would be the one to get.
y5mgisi
1 ton status
I agree. They will all work great for you.
Just to add to Larry's testament a bit...
I DD an 03 Tahoe Z71 with a 5.3L / 4l60e right now. On the highway I average about 18 mpg with it. Mixed city / highway is closer to 16 mpg. Like Larry mentioned, the 5.3L does NOT have much for grunt. I've got the torque management and abuse protection all deleted on it, the engine does not pull any stops anymore to protect the transmission. I can neutral drop the thing into drive from 6000 RPM if I wanted to (stock won't allow this). Basically the engine makes power above 4500 rpm, below that it just makes noise but doesn't really pull. It works, yes, but it is definitely lacking torque to motivate that big ol' 4 door Tahoe to get moving in a hurry.
A 6.0L will feel much more athletic, but the mileage will drop down considerably to at best 16 mpg on the highway, 12 - 13 mpg mixed city / highway. My father barely made that number real world with his last 6.0L truck and always complained about the mileage it was getting vs the Tahoe (boohoo, 2 mpg difference, LOL!). The engine was also a gutless wonder when you put a trailer behind it and the mileage would drop into the single digits pretty dang quick.
An 8.1L will get between 14 - 15 mpg on the highway, around 11 or 12 mixed city / highway. That's not a whole lot less than the 6.0L for a whole lot more engine. The torque is in a much more useful part of the power band and the truck effortlessly is launched to whatever speed you want pretty much right now. Stock for stock, an 8.1L will out-accelerate an LB7 Duramax diesel engine which it initially competed against. The big blocks pull and accelerate just like a diesel engine does but doesn't pull down the same fuel economy which is why they didn't sell well compared to the diesel engine.
Lets say you put a 5.3L engine into your Blazer and went on a trip to Alaska and back. That's about 6500 miles round trip assuming you only make 500 or so miles of side trips along the way. That means that getting 18 mpg you'll be burning around 360 gallons of fuel. A 6.0L getting 16 mpg will burn around 400 gallons of fuel. An 8.1L getting 14 mpg will burn around 460 gallons of fuel.
Say fuel is 3.80 a gallon on average across the trip, that means you'll be spending $1370 for the 5.3L, $1520 for the 6.0L and $1750 for the 8.1L. That's a difference of only $380 in fuel between the 5.3L and the 8.1L within 6500 miles of driving. Frankly, if your budget for a trip is so tight that $400 will make or break it, you should probably save up a bit more of a contingency before you leave anyways!
An 8.1L will not have any added expenses for regular maintenance over an LS engine like a Diesel engine does (no fuel filters, more expensive oil / coolant, air filters etc) but provides all the power of one. The fuel mileage thing is something everyone really obsesses over but really makes relatively little difference in the long run. When it comes to calculating the cost of a vehicle fuel is by far and large the smallest component of that calculation when compared to the cost of depreciation, maintenance, wear items, insurance, registration etc.
I've seen people sell a vehicle that they already own and purchase a new vehicle over 4 or 5 mpg. There is simply no payout in a deal like that. Suddenly you are paying interest, higher repair costs, higher insurance, more expensive maintenance etc for a measly $400 in fuel savings over 6500 miles of driving.
Ultimately, its up to you to make the call, but I do genuinely believe you'd be happier with the on and off road performance of a larger engine than a 5.3L. Be it a 6.0L or 8.1L it makes no difference to me. I like the big block because of how much more engine you get for very little added cost. I like the idea of making reliable power out of a stock engine vs modifying one to make the same power out of a smaller displacement.
I DD an 03 Tahoe Z71 with a 5.3L / 4l60e right now. On the highway I average about 18 mpg with it. Mixed city / highway is closer to 16 mpg. Like Larry mentioned, the 5.3L does NOT have much for grunt. I've got the torque management and abuse protection all deleted on it, the engine does not pull any stops anymore to protect the transmission. I can neutral drop the thing into drive from 6000 RPM if I wanted to (stock won't allow this). Basically the engine makes power above 4500 rpm, below that it just makes noise but doesn't really pull. It works, yes, but it is definitely lacking torque to motivate that big ol' 4 door Tahoe to get moving in a hurry.
A 6.0L will feel much more athletic, but the mileage will drop down considerably to at best 16 mpg on the highway, 12 - 13 mpg mixed city / highway. My father barely made that number real world with his last 6.0L truck and always complained about the mileage it was getting vs the Tahoe (boohoo, 2 mpg difference, LOL!). The engine was also a gutless wonder when you put a trailer behind it and the mileage would drop into the single digits pretty dang quick.
An 8.1L will get between 14 - 15 mpg on the highway, around 11 or 12 mixed city / highway. That's not a whole lot less than the 6.0L for a whole lot more engine. The torque is in a much more useful part of the power band and the truck effortlessly is launched to whatever speed you want pretty much right now. Stock for stock, an 8.1L will out-accelerate an LB7 Duramax diesel engine which it initially competed against. The big blocks pull and accelerate just like a diesel engine does but doesn't pull down the same fuel economy which is why they didn't sell well compared to the diesel engine.
Lets say you put a 5.3L engine into your Blazer and went on a trip to Alaska and back. That's about 6500 miles round trip assuming you only make 500 or so miles of side trips along the way. That means that getting 18 mpg you'll be burning around 360 gallons of fuel. A 6.0L getting 16 mpg will burn around 400 gallons of fuel. An 8.1L getting 14 mpg will burn around 460 gallons of fuel.
Say fuel is 3.80 a gallon on average across the trip, that means you'll be spending $1370 for the 5.3L, $1520 for the 6.0L and $1750 for the 8.1L. That's a difference of only $380 in fuel between the 5.3L and the 8.1L within 6500 miles of driving. Frankly, if your budget for a trip is so tight that $400 will make or break it, you should probably save up a bit more of a contingency before you leave anyways!
An 8.1L will not have any added expenses for regular maintenance over an LS engine like a Diesel engine does (no fuel filters, more expensive oil / coolant, air filters etc) but provides all the power of one. The fuel mileage thing is something everyone really obsesses over but really makes relatively little difference in the long run. When it comes to calculating the cost of a vehicle fuel is by far and large the smallest component of that calculation when compared to the cost of depreciation, maintenance, wear items, insurance, registration etc.
I've seen people sell a vehicle that they already own and purchase a new vehicle over 4 or 5 mpg. There is simply no payout in a deal like that. Suddenly you are paying interest, higher repair costs, higher insurance, more expensive maintenance etc for a measly $400 in fuel savings over 6500 miles of driving.
Ultimately, its up to you to make the call, but I do genuinely believe you'd be happier with the on and off road performance of a larger engine than a 5.3L. Be it a 6.0L or 8.1L it makes no difference to me. I like the big block because of how much more engine you get for very little added cost. I like the idea of making reliable power out of a stock engine vs modifying one to make the same power out of a smaller displacement.
if Colby decides to go a different route, when we do get to make offers on the setup?
dibs for second in line haha.
dibs for second in line haha.
79rustyk10
3/4 ton status
Now I want an 8.1 truck even more.
Both of my trucks are diesels mainly because I'm a diesel nut 
. But if my step-side wasn't diesel powered it would have a either a 496 or a ramjet 502.
Another good reason for you to get it from Russel is that getting the matching trans makes it a very good deal. My friend paid around $3k for a used 6.0 that he put in his buggy. That was just the engine, no trans. Did include the harness with the mods he needed done to it though.
Besides its a BIG BLOCK!!!! GO BIG or GO HOME!!!
. But if my step-side wasn't diesel powered it would have a either a 496 or a ramjet 502. Another good reason for you to get it from Russel is that getting the matching trans makes it a very good deal. My friend paid around $3k for a used 6.0 that he put in his buggy. That was just the engine, no trans. Did include the harness with the mods he needed done to it though.
Besides its a BIG BLOCK!!!! GO BIG or GO HOME!!!
Fubeca
1/2 ton status
Btw - what year is it? I think my 8.1 has a 4l85e behind it - ever-so-slightly beefier than the 4l80e.
There is a nice 2001 (?) Suburban on the Boston CL with an 8.1 in it,has a dent in one rear quarter,otherwise looks new,loaded,only 3500 bucks!..140K on it though.but still cheap!..
modernbeat
1/2 ton status
First, I'm in the middle of sticking an 8.1L, NV4500 and NP205 in my 1976 K25.
And, I work at a shop that does a LOT of LSx swaps into cars.
Unless you source your 8.1L from a van and get all the accessories with it, you will end up spending $1500-2000 to put all the parts together for the big block over the LS engine.
Putting together either a 6.0 or a 5.3 cost the same after the cost of the longblock. And the parts are easy to buy either new or used. Lots of people strip off the stock intakes, throttle bodies and accessories for hot rod parts. The big blocks are hard to buy those parts on the used market.
But, it might be worth it. And for a truck application, I certainly think the big block is.
And, I work at a shop that does a LOT of LSx swaps into cars.
Unless you source your 8.1L from a van and get all the accessories with it, you will end up spending $1500-2000 to put all the parts together for the big block over the LS engine.
Putting together either a 6.0 or a 5.3 cost the same after the cost of the longblock. And the parts are easy to buy either new or used. Lots of people strip off the stock intakes, throttle bodies and accessories for hot rod parts. The big blocks are hard to buy those parts on the used market.
But, it might be worth it. And for a truck application, I certainly think the big block is.
Russell, Larry: You're making some very convincing points... 
If I can get essentially the same fuel economy as my current TBI provides, I'd be fine with that. Russell, we'll talk more via PM in the next few days.
As to laws on what engine can be installed in a vehicle: I am not convinced that there's a Federal law that requires it. There's no inspection in NV or OR (the two places I've lived with a K5). I did/do happen to live in places in both states that required emissions testing, but they just put a sniffer on it and check to make sure there is no visible smoke. So, no government organization is tracking what engine is in there at all in either of those states. I will never live in CA, so that shouldn't be a problem. It's looking like I'll be moving back to OR a couple years from now. I also lived in Seattle, WA, but I didn't have a K5 then - just an S10 Blazer - and I don't think they have inspection either, just emissions. Come to think of it, Phoenix, AZ was the same way - again, not having a K5 and thus not considering these issues....
If I can get essentially the same fuel economy as my current TBI provides, I'd be fine with that. Russell, we'll talk more via PM in the next few days.As to laws on what engine can be installed in a vehicle: I am not convinced that there's a Federal law that requires it. There's no inspection in NV or OR (the two places I've lived with a K5). I did/do happen to live in places in both states that required emissions testing, but they just put a sniffer on it and check to make sure there is no visible smoke. So, no government organization is tracking what engine is in there at all in either of those states. I will never live in CA, so that shouldn't be a problem. It's looking like I'll be moving back to OR a couple years from now. I also lived in Seattle, WA, but I didn't have a K5 then - just an S10 Blazer - and I don't think they have inspection either, just emissions. Come to think of it, Phoenix, AZ was the same way - again, not having a K5 and thus not considering these issues....
y5mgisi
1 ton status
Oh boy... Just checked car-part.com. Looks like the 8.1 actually runs a little CHEAPER than the 6.0's! Im for sure going to have to get one.
y5mgisi
1 ton status
Here is a Dyno chart from GM for the 03 L18.
Russell, Larry: You're making some very convincing points...
As to laws on what engine can be installed in a vehicle: I am not convinced that there's a Federal law that requires it. There's no inspection in NV or OR (the two places I've lived with a K5). I did/do happen to live in places in both states that required emissions testing, but they just put a sniffer on it and check to make sure there is no visible smoke. So, no government organization is tracking what engine is in there at all in either of those states. I will never live in CA, so that shouldn't be a problem. It's looking like I'll be moving back to OR a couple years from now. I also lived in Seattle, WA, but I didn't have a K5 then - just an S10 Blazer - and I don't think they have inspection either, just emissions. Come to think of it, Phoenix, AZ was the same way - again, not having a K5 and thus not considering these issues....
Colby, when the shop starts the emission testing part of the test is to make sure that the engine that is in the vehicle belongs there (in your case a conventional old school SBC and nothing else). If they see a BBC or even an LS engine they will now send you to a referee station to have it tested the first time.
Xtremegmc80
1/2 ton status
Go big block. Ever since I tuned my duramax with efi live I cant even image myself driving a stock trucks anymore, now im mAking in the neighborhood of 550 horsepower and is not done. Plus pull 20-21 mpg on a long flat highway. When towing it drops to around 12-16 depending on weight. And my right foot. Alot of time I go real easy when towing.
That being say I test drove a 6.0l when i was thinkin abt trading it in before. I was instantly disappointed with the power of it. A friend of mine has the 8.1 big block in his truck, i liked it ofc it does not compare to my dmax but hey i would own it over a 6.0. Thats how disappointed I was with the 6.0, even my little 4.8 truck with blackbear tune felt more power for a stock 6.0. Until later i found out their all ridiculously detuned from the factory.
That being say I test drove a 6.0l when i was thinkin abt trading it in before. I was instantly disappointed with the power of it. A friend of mine has the 8.1 big block in his truck, i liked it ofc it does not compare to my dmax but hey i would own it over a 6.0. Thats how disappointed I was with the 6.0, even my little 4.8 truck with blackbear tune felt more power for a stock 6.0. Until later i found out their all ridiculously detuned from the factory.
Xtremegmc80
1/2 ton status
Damn! press send before I was even done and not done with correcting my sentences. Sorry guys.
Point of the story. Go big, you will be happy plus when the guys/ gals ask u whats under the hood. *its a big block* sounds much cooler.
Dont do the dmax or cummins swap it cost alot more, and would be suit better for a towrig.
I know this. Cause I have a 355 dirt race track motor in my 1980 gmc now. And im collecting parts for a cummins swap now.
Point of the story. Go big, you will be happy plus when the guys/ gals ask u whats under the hood. *its a big block* sounds much cooler.
Dont do the dmax or cummins swap it cost alot more, and would be suit better for a towrig.
I know this. Cause I have a 355 dirt race track motor in my 1980 gmc now. And im collecting parts for a cummins swap now.
It appears NV is pretty lenient on vehicle inspections.
http://www.dmvnv.com/emission.htm
Like Mass, the inspection stations are privately owned, not state run like Cali.
Looks like they have a sniffer test very much like we used to have here. If they don't even open the hood they will never know anything is different. And, being privately owned means it's up to the inspection tech to decide if anything is out of place, not a state paid employee.
Colby, I really think you will not have an issue with an engine swap in your K5 with an LS or the 8.1 as either of those choices run cleaner than the old TBI ever will.
I don't think any other state has referee stations besides Cali. Some states don't even have emissions testing at all. Even scarier, some don't have safety inspections
. That's not to say you can just go cutting cats or emissions equipment off of any vehicle in these states (even though people do 
) but it's much less regulated to pass emissions in states outside of Cali.
http://www.dmvnv.com/emission.htm
Like Mass, the inspection stations are privately owned, not state run like Cali.
Looks like they have a sniffer test very much like we used to have here. If they don't even open the hood they will never know anything is different. And, being privately owned means it's up to the inspection tech to decide if anything is out of place, not a state paid employee.
Colby, I really think you will not have an issue with an engine swap in your K5 with an LS or the 8.1 as either of those choices run cleaner than the old TBI ever will.
I don't think any other state has referee stations besides Cali. Some states don't even have emissions testing at all. Even scarier, some don't have safety inspections
. That's not to say you can just go cutting cats or emissions equipment off of any vehicle in these states (even though people do ) but it's much less regulated to pass emissions in states outside of Cali.
There's no safety inspections here, and you're right: The emissions stations are privately owned. The place I usually go to has employees that wouldn't know the difference between a 4 cylinder Toyota engine in my K5 and a BB. When they check the VIN, they're just verifying that you are in fact getting the emissions tested for the particular registration card you're showing them. I could go to the next county over and never have anyone look at my vehicle for any reason and I could still register/drive it. You should see some of the strange 4x4s that drive around on the streets here. Narrowed front/rear? No problem.
