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My 5.3 swap thread!

Or i could just pull off my access panel and not mess with it. \



The 5.3 is 100hp and 35lb.ft increase over the stock tbi 350. I think it should be a significant increase. Dont think the th400 will ever hunt unless im pulling a big load on a big hill.

5.3L-> 270-305 hp (313-320 kW) and torque is 315 lb·ft (427 N·m) to 335 lb·ft (454 N·m) Not sure why the stated range differences.

Stock I think is 220hp 265 torque. So not quite 100 hp more would be 50-85hp more I guess. Still a huge improvement. My problem was precisely that large load, large hill. Same with the buddies truck with the 5.3L he said it would always downshift and peg the rpms to get up a hill towing a load. I wanted to make sure I didn't have that problem again. He ended up selling his truck and getting a 2012 Ford diesel with 800 lbs of torque lol. My only other option probably would have been the 6.0L.
 
Look for the L33...

With a compression ratio of 9.9:1 in 2007, this engine could produce 315 horsepower at 5,200 rpm and 338 foot-pounds of torque at 4,400 rpm.

The L33 was available only in the four-wheel drive, extended-cab versions of vehicles like the Chevrolet Silverado and GMC Sierra from 2005 until 2007. In 2005, the first year of the L33's production, only about a quarter of GM's trucks featured this engine.

Keep in mind the L33 is an all aluminum engine too...over 100 lbs lighter than the iron block aluminum head version of the 5.3.

Stock TBI 350 numbers I recall are 210 hp and 300 ft/lbs of tq. The "equalizer" IMO is the TBI 350 makes it's peak tq at a much lower rpm. Frankly if GM had the foresight to slap better heads on the TBI 350 so it'd actually rev and make power beyond 4500 rpm the hp numbers would look a lot more favorable.

The fact a truck with a 5.3 will drop a gear and rev pulling a load up a hill is a factor of where the engine makes it's best power. As you can see peak torque is right where peak hp was for the TBI 350...4400 rpm.
 
Look for the L33...

Stock TBI 350 numbers I recall are 210 hp and 300 ft/lbs of tq. The "equalizer" IMO is the TBI 350 makes it's peak tq at a much lower rpm. Frankly if GM had the foresight to slap better heads on the TBI 350 so it'd actually rev and make power beyond 4500 rpm the hp numbers would look a lot more favorable.

The fact a truck with a 5.3 will drop a gear and rev pulling a load up a hill is a factor of where the engine makes it's best power. As you can see peak torque is right where peak hp was for the TBI 350...4400 rpm.
I've seen all kinds of numbers for the stock TBI I dont know what's accurate. I've seen 210-220 hp and the torque I thought was 265.

As far as the 5.3L and hunting I have no personal experience with it. I just know my friend always complained going up the same hill as I always complained about going up while towing a load. That's why he went to the Ford diesel. I just figured if he had problems then I would have had them to. Since the OP is from Oregon he would know the hill, sylvan hill on highway 26.

Seems like a cool motor and a neat project. Just the fuel economy improvements make it a worthy upgrade. From what I have seen on other forums it takes to upgrades nicely also.
 
I've seen all kinds of numbers for the stock TBI I dont know what's accurate. I've seen 210-220 hp and the torque I thought was 265.

As far as the 5.3L and hunting I have no personal experience with it. I just know my friend always complained going up the same hill as I always complained about going up while towing a load. That's why he went to the Ford diesel. I just figured if he had problems then I would have had them to. Since the OP is from Oregon he would know the hill, sylvan hill on highway 26.

Seems like a cool motor and a neat project. Just the fuel economy improvements make it a worthy upgrade. From what I have seen on other forums it takes to upgrades nicely also.


I've towed some with the 5.3, and really, its designed to run at those higher RPMS for long periods of time.

Granted, a non stock tuned 5.3 is a little more capable, the last time i drove a 5.3 in a burb i was less than impressed. They do great in the tahoe, but if i do an LS swap it will be a 6.0 for the weight of what i do.
 
Yea a 5.3 is really not he best choice for a suburban. But neither is a tbi 350! So the mpg, HP, tq increases make it a worthy upgrade but It's still never going to be all that a 6.0 or 383 will be for power. For me the reason for going 5.3 had a lot to do with cost. Mine is going to end up around $1600 all done. The 6.0s seem to go for around $1200 average and seem to get a couple less mpg over the 5.3. All that meant for me that a 5.3 was the best choice.
 
Yea a 5.3 is really not he best choice for a suburban. But neither is a tbi 350! So the mpg, HP, tq increases make it a worthy upgrade but It's still never going to be all that a 6.0 or 383 will be for power. For me the reason for going 5.3 had a lot to do with cost. Mine is going to end up around $1600 all done. The 6.0s seem to go for around $1200 average and seem to get a couple less mpg over the 5.3. All that meant for me that a 5.3 was the best choice.


Understood, not trying to criticize your decision.

Just wanted to express what i'd found towing performance wise.
 
My wife has a 2007 2WD suburban with a 5.3. The milage should be better then what she gets (10 to 12 in town and 16 to 18 on the highway), as far as power it got good overall power.

I had a 98 excab 2500 with a 6.0L and it only got about 12 most of the time.

As far as horsepower, 325 shouldn't be that bad.

As far as hunting gears that has more to do with gear ratios in the tranny then the power of the motor. to many people try to tow in overdrive. I have a duramax with a 6 speed allison, and it has a harder time towing my 30' travel trailer in 6th gear then 5th because the rpm are to low.
 
I'm sure if you left it in drive it wouldn't hunt between gears when I towed my k5 with my 01 1500 with a 5.3 as long as I left it in drive it was fine. If I shifted to overdrive it would hunt.
 
Yea a 5.3 is really not he best choice for a suburban. But neither is a tbi 350! So the mpg, HP, tq increases make it a worthy upgrade but It's still never going to be all that a 6.0 or 383 will be for power. For me the reason for going 5.3 had a lot to do with cost. Mine is going to end up around $1600 all done. The 6.0s seem to go for around $1200 average and seem to get a couple less mpg over the 5.3. All that meant for me that a 5.3 was the best choice.
Wasn't trying to down play your upgrade either. I'm envious of the new technology you get to use just sucks it wouldn't have worked for me. It's a cool upgrade no matter what. I don't know if it can't be all that a 383 can be either. From what I have read on some other forums it takes to upgrades nicely. I don't know what the limit is on that motor if you start upgrading it.
 
No its all good. But yea, looks like a zo6 cam and a set of long tube headers is good for a fair bit! Toss a turbo in the mix and your really talkin! They are crazy strong too. There was an article in hot rod magazine where they tried to blow up a junk yard 5.3 by boosting it to smitherines. In the end, they were making over 1200hp on a STOCK junk yard bottom end that turned out to actually be a 4.8L!
 
No its all good. But yea, looks like a zo6 cam and a set of long tube headers is good for a fair bit! Toss a turbo in the mix and your really talkin! They are crazy strong too. There was an article in hot rod magazine where they tried to blow up a junk yard 5.3 by boosting it to smitherines. In the end, they were making over 1200hp on a STOCK junk yard bottom end that turned out to actually be a 4.8L!

That's awesome! I love those articles. What a great job to take motors and push em till they grenade.

Keep up the good work!

Sent from my Droid2 via Tapatalk...enabling the CK5 sickness
 
Oh I forgot to add that they never did blow it up... They had maxed out their turbos at 26psi and were out of dyno time.
 
No its all good. But yea, looks like a zo6 cam and a set of long tube headers is good for a fair bit! Toss a turbo in the mix and your really talkin! They are crazy strong too. There was an article in hot rod magazine where they tried to blow up a junk yard 5.3 by boosting it to smitherines. In the end, they were making over 1200hp on a STOCK junk yard bottom end that turned out to actually be a 4.8L!

Not sure I would want to deal with a turbo but a new cam and some tuning could probably get you some nice gains. Your starting from a far superior engine management system. On my 383 I'm working with lawn mower technology :haha:

Would be cool to check out your truck when you're done. I see you're in Portland. I get down that way every weekend usually. Good luck with the build.
 
No he said they should be here friday. We'll see. The ones that were on there he said were no good and the harness for them was fugged up. So he had been looking for a set and found some to send me.
 
No he said they should be here friday. We'll see. The ones that were on there he said were no good and the harness for them was fugged up. So he had been looking for a set and found some to send me.
at least he is solving the problem.
 
Man, life has slowed this down to nearly a stand still! Still holding out hope for a weekend test start but It's looking worse every day.
 
Man, life has slowed this down to nearly a stand still! Still holding out hope for a weekend test start but It's looking worse every day.

I know the feeling, I wish I had a few days to just finish up all the small stuff so I can get mine fired up too.
 
Stupid small stuff... I could definitely start mine Saturday night if I started on it Saturday morning. But, who knows if that's going to work out. Oh well. Just practicing my patients in the mean time.
 

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