Chevy engine swap

[buickanddeere]

Do your homework as newer 5.3 and 6.0 engines build their HP at much higher 5200 RPM that your TBI 350 4000 RPM engine is capable of running.

Your 1995 Chevy 2500 350 might be a TBI (Throttle Body Injection) LO5 engine (VIN letter K) rated at 205 HP at only 4000 RPM and 310 Ft-Lb torque at 2400 RPM. The 1996-2000 Vortec L31 engine was rated 255 HP at 4600 RPM and 330 Ft-Lb torque at 2800 RPM mostly from different cylinder heads and MPI (Multiport Fuel Injection). Your TBI cylinder heads have no chance of flowing enough air to build HP at higher RPM, the bottom end might not be capable of higher RPM either. If you do stay with a 350 investigate if a new crate engine is available already built to meet your goals rather than try to rebuild your old engine yourself.

The 2000 and up 5.3 and 6.0 made their HP at 5200 RPM and maximum torque at 4000 RPM. Transmissions are different with shift points at higher RPMs. The internet is full of information from people who have made that swap.

TBI 350 vs. gen III 5.3l LM7

So, my Blazer has a perfectly good TBI 350 with a brand new 700R4 behind it. The plan was to put on some Vortec heads, a cam, bigger throttle body and a chip and hope I get somewhere close to 300 HP. However, I'm picking up a 2000 chevy with a 5.3l and 4l60e this weekend. Would you yank...

www.rme4x4.com

The Canadian 906 induction hardened heads on the L31 are more durable than the Mexican 062 heads .
The L31 only needs a mild cam upgrade and an after market aluminum intake .

 

[Texasmark]

It’s throttle body now and the 350 only has 40,000 miles on it.I just want more hp for pulling a trailer.a better throttle body and intake for the 350 is an option.I’ll call Holley tomorrow to pick their brains

I think my 1989 Tahoe 350 had the throttle body...electronic control fuel delivery at the air inlet, not Mult Port Fuel Injection (squirter at each intake valve), which is much more precise. But it worked ok. May be less items to convert if TB rather than MP. I bought it used with moderate miles. Had a radiator fluid leak at the intake manifold and block intersection. Upon removing the manifold the sealer between the surfaces looked like a monkey applied it. I think I scraped all that crap off and installed a Feld-Pro O-ring in an aluminum housing which was bullet proof. The aluminum frame insured that the seal was perfect as it limited the distance between the manifold and the block. Feld Pro specified the torque when reinstalling and it wasn't a lot.

Recalling the engine had wires going to sensors all over the place and removing them to get the manifold out seemed to be challenging. What I did was to block up the hood so that it wouldn't close and with a couple of ropes, hanging from the hood, held the manifold above the block several inches with almost all the wiring intact while I fixed the gasket problem.

I think the MP fuel pressure is something like 40 PSI on the rails. Don't know what the TB requires.

 

[rrman61]

I think my 1989 Tahoe 350 had the throttle body...electronic control fuel delivery at the air inlet, not Mult Port Fuel Injection (squirter at each intake valve), which is much more precise. But it worked ok. May be less items to convert if TB rather than MP. I bought it used with moderate miles. Had a radiator fluid leak at the intake manifold and block intersection. Upon removing the manifold the sealer between the surfaces looked like a monkey applied it. I think I scraped all that crap off and installed a Feld-Pro O-ring in an aluminum housing which was bullet proof. The aluminum frame insured that the seal was perfect as it limited the distance between the manifold and the block. Feld Pro specified the torque when reinstalling and it wasn't a lot.

Recalling the engine had wires going to sensors all over the place and removing them to get the manifold out seemed to be challenging. What I did was to block up the hood so that it wouldn't close and with a couple of ropes, hanging from the hood, held the manifold above the block several inches with almost all the wiring intact while I fixed the gasket problem.

I think the MP fuel pressure is something like 40 PSI on the rails. Don't know what the TB requires.

Thanks for all replies.looks like I’ll just stay with the 350.needed real world experience and what better place to ask than here from people who have been there

 

[Mark-Ia]

What is a 5.4L

5.4 is a Ford engine.

 

[Sprint 6]

Staying as built amd modifying that is always the best choice. Glad you chose that route. If you were dead set on a swap, I would skip the 5.3 and go straight to a 5.9 P-pump Cummins.

For posterity, since others may find this post in the future, while the 4L80E will bolt directly to a 5.3, one needs the crank spacer and flex plate from a 6.0 to not pull the torque converter out too far. The 5.3 has a flush crank at the bellhousing, while the 4L80E requires a crank that sticks out. The 4L80E integral bellhousing was never redesigned to accommodate the flush crank, it still needs traditional SBC, BBC crank spacing.

As to modifying the TBI engine. Don't. The TBI engine is reliable, but its ECM operates on several assumptions. The biggest assumption is the engine's volumetric efficiency (VE), or how much air the engine pumps per revolution. Any modifications that change the VE, the ECM cannot adapt to them due to no Mass Air Flow sensor. Any modified TBI engine I've been around just used more fuel and made no more power. Tuning can be done, but the PROM chip has to be burned with the mods, and the equipment to do that yourself has been off the market for several years. There are companies that do it still, but its a pain. I had a customer that didn't heed my warnings trying to get a custom PROM burned for an early LT1 Firebird. Last I knew, he gave up trying to get it right after several paid attempts and sold the car.

 

[buickanddeere]

How hard would it be to swap out my 350 and replace it with a 2004 5.4 in my 95 Chevy 2500 with 4L80 transmission?everything needed for the 5.3 is there on the engine less whatever it takes to swap it over

Any left over 2025 pickups on the dealer’s lot gathering dust ?

This equipment ends fuel and air supply challenges . Would pay for its self in fuel savings vs a carburetor .

 

[paulsamwel]

How hard would it be to swap out my 350 and replace it with a 2004 5.4 in my 95 Chevy 2500 with 4L80 transmission?everything needed for the 5.3 is there on the engine less whatever it takes to swap it over

Common swap.Lots of info and support on the net.