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Should I swap to a 6.2/6.5?

dyeager535 said:
The 4/6BT's all require a lift of some sort though, correct?

I know a few have swapped those into these rigs, I can't recall who though. I would expect a 3.9L should get significantly better MPG than the 6.2/6.5?
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If you want a decent amount of uptravel, yes, some lift. Mine (6BT) is 3" of suspension lift and I have 4-1/2" of uptravel, so you could do it near stock height with very little uptravel. Personally, I wouldn't do it without a couple inches of lift at least.
 
That puts it out of the running then.

Did I not hear of people getting 30MPG out of the 4BT's?
 
I like the 6.2's for plowing,off road use,they are well suited to those chores--it's hard to stall a 6.2 with a manual trans,as its governed idle prevents that,makes for good crawling capeability..the low end grunt makes it a good "work truck" for pushing snow,and the lack of HP actually helps in that situation..towing though,I dont think they are that good at...a friend had a '87 C-30 ramp truck with a 6.2 / SM 465 and it was a real slug with a car on the bed...it eventually snapped the crankshaft without warning while just cruising along about 40 mph empty one day..:eek1:

As a daily driver though,I would rather just have a gas engine,gas is cheaper ,it'll start at any temprature,and not lack power on hills and take offs..
I like diesels,but the 6.2 gets tiring to listen too,you feel like your driving a tractor or backhoe instead of a truck,and somehow,to me it makes a short trip seem a lot longer...

My truck seldom goes more than a few thousand miles a year,that is the main reason I've left it as is,I dont feel it is worth all the work and expense to swap in a gas engine now that it is getting long in the tooth as far as rust and old age catching up with it..
 
Im building an A M General 6.5 with a Gail Banks turbo, turbo 400, 205 and Gear Vendors overdrive with 456 and 37s, I'm shooting for 20mpg.

my buddy has an H1 with 6.5 n.a. he gets 10mpg on the street and 35mpg off road.
 
Around here, the ticket for savings has not been diesels, but flex fuel vehicles. I've been paying $0.86 to $1.38/gallon since December. Even though I get just 13MPG from it, with diesel at $2.90 you need 44MPG to match the economy. However, e85 reduces your range since you need like 25% more than gas to make stoich. Plus, it's harder to find.

Increase range? 2x 5-gallon jerry cans = 150 extra miles. Done. Also, when you do need to run for fuel, gas is easier to find than diesel.

Where are you going that a 31-gallon K5 tank plus a couple of Jerry cans isn't enough?
 
I have a '90 K5 with the 6.2/TH700r4/3.73 setup that I bought in 1994 with 49k on the ticker. The only non-stock item were the 32" mud tires....this was verified a few years ago when I met the original owner at my new job. Point being it was stock and not ragged out when I bought it.

It consistently got 18 mpg with mostly city and back road (lots of stop and go) and was always ran with my foot on the floor. That was 90% of my driving back then and never really check mileage during the few longer highway trips, but pretty sure it would of gotten 20 mpg easily at any reasonable speed. It would easily cruise at 75 mph down the highway and I got a couple of speeding tickets to prove it, and would touch the 85 mph on the speedo on a back road before having to back out of the throttle.

With that said, by no means was it a rocket ship but it was "okay" for daily driving. My 2500HD 6.0L/4.10 equipped truck will run circles around it on the road but I would love to have another mostly stock K5 with the 6.2 to drive everyday.

Off-road the 6.2 is great in most situations. Those few times when you need a lot of wheel speed, like a long greasy hill, is where it is lacking. Crawling and low speed stuff, along with fuel range, is awesome with the 6.2.
 
I normally head up to the mountains for ~10 days, each day is probably spent gaining 5-10000ft, no idea on mileage, it varies. But under those conditions I'm lucky to see 10MPG all day. As it is, with the 100 gallon spare tank I've got plenty, but that's now because I'm the only one running gas. When more rigs ran gas, it was just about right. As it is now, all the diesel guys have to run back out at least once to fill up. Depending on conditions, it is a run you might not want to do if you had a choice.
 
my '91 3/4 ton Sub with 6.2 got a running average of 19 mpg stock.

swap in D60/14 bolt with 4.10s and 33"x12.4 BFGs and it gets 16 mpg now. this is running average, not cherry picked...
 
I have a 4bt/nv4500 in my old clapped out 78 k10. 25 mpg all day long with 4" lift and 33s and 3.73s. I have broken the 30mpg limit one trip.

I really like the way it runs. Feels like a bit more power than the 6.5/4l80 I had in a 94 2 door blazer.

I actually bought a cherry 90 k5 to swap the 4bt combo into. But with gas prices where they are, I have not made the leap to go through with the labor. Plus the tbi 350/700 runs so nice and is quiet.

The 4bt runs great. But it is loud. That has been one of my hang-ups in committing to swapping to the K5. It would fit in a stock height blazer with just a bit of oil pan massaging and not limit up-travel from stock.
 
I've had a couple 6.2's and frankly, with all the people swapping in LS engines I'd do that if we are talking an engine swap. Twice the power than a 6.2 and lots better mileage than the old small blocks.
 
A 6.2 is NOT a Detroit.

Have you thought about just buying a different Blazer that already has a 6.2 in it? I am not sure what is all done to your Blazer? I don't know if you have a lot of emotional attachment to it?

How set are you on a manual transmission? The TH700R4 was the only transmission available with a 6.2 in a Blazer or Jimmy.

Martin
 
82355 said:
A 6.2 is NOT a Detroit.

Have you thought about just buying a different Blazer that already has a 6.2 in it? I am not sure what is all done to your Blazer? I don't know if you have a lot of emotional attachment to it?

How set are you on a manual transmission? The TH700R4 was the only transmission available with a 6.2 in a Blazer or Jimmy.

Martin
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Actually, it is a Detroit diesel engine. GM didn't make them.
 
82355 said:
Have you thought about just buying a different Blazer that already has a 6.2 in it? I am not sure what is all done to your Blazer? I don't know if you have a lot of emotional attachment to it?
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I suppose if the right one fell in my lap I'd be inclined to take it. All my emotional attachment can be unbolted.

82355 said:
How set are you on a manual transmission? The TH700R4 was the only transmission available with a 6.2 in a Blazer or Jimmy.
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I won't own a vehicle without a manual, at least that I buy now.

But this is just shop talk now, it's pretty obvious the 6.2 is not a wonder motor. The 4BT is quite tempting (30MPG? 900 mile range?? drool) , but I think that opens up another can of worms that begins to approach the "just forget the idea" zone.
 
82355 said:
A 6.2 is NOT a Detroit.

Have you thought about just buying a different Blazer that already has a 6.2 in it? I am not sure what is all done to your Blazer? I don't know if you have a lot of emotional attachment to it?

How set are you on a manual transmission? The TH700R4 was the only transmission available with a 6.2 in a Blazer or Jimmy.

Martin
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The m1009 had the 6.2/th400 combo.

My old 1009 with the stock drivetrain, lifted 4" on 37s got about 18mpg highway driving. Seems like range is what you are looking for the most. I would consider a ls swap and larger fuel tank. I think you could swap the larger suburban 40+gallon tank into your truck without too much hassle
 
Interesting topic. My CUCV has the 6.2, and I really like it. The power never bothered me, running 35's. The main issue is that with the TH400 and 4.56's, it can't even be driven on the interstate. I don't take it above 60 or so.

If the TBI 350 in the K5 exploded, I'd be tempted to drop in a 6.2, for no other reason than the dirt simplicity of it. I love the almost complete lack of wiring and electronics, but that's just me.

:popcorn:
 
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