I currently have a 98 xcab sonoma with a busted 2.2l and i found a 99 reg cab sonoma with a good 4.3l trans and cpu. My question is what other mods will need to be done and fill most of the parts fit my 98? I could really use some help. Is it even worth making the swap?
Motor swap to 4.3l help!!!
- Thread starter docwatson
- Start date
Molson02536
New member
At this point, wait and look for a 4.8 or a 5.3 vortec with transmission and PCM. If your going to do a swap, might as well make it worth the hard work on doing it. Plenty of 4.8 vortec out in the world for cheep price.
All you will need is new engine mounts and electric radiator fan, and a added stopping power is to swap out your brake booster with a larger one from a Corvette.
Keep us posted and feel free to ask any more questions you me have
The problem is money. I found the donor truck with 4.3 vortec for $600 and full swap for about $800 so i dont know if i will be able to find a 4.8 at such a good price with such a limited budget. So would the donor 4.3 work?
Molson02536
New member
Will work, just don't forget to replace the engine and transmission mounts. Take your time and make sure when swaping your ECM and wire harness, that there are no shorts or broken connections.
Good luck and keep us posted.
hackettsautomotive
New member
Would it matter the type of 5.3 Vortec? LM7, LM4, or L33?
I was interested in fitting a 350 inside my Sonoma, but I think a 5.3 Vortec would suit me just fine..
Molson02536
New member
The LM7 (VIN code "T") Vortec 5300 was brought in 1999 on there full size trucks like the Escalade, and can be considered the "garden variety" version of the Generation III 5.3 liter V8's.
The LM7 has an iron block and aluminum heads as to the LM4 (VIN code "P") Vortec 5300 is an aluminum block version of the LM7, and had a short production life. of 03-04 found in the Trailblazer ext ect.
The L33 (VIN code "B") is an aluminum block version of the LM7, and was referred to as the Vortec 5300 HO version of the LM4. Power increased by 15 hp to 310 hp, but the torque was unchanged. It was only available on extended cab 4WD pickup trucks. Only 25% of trucks made in 2005 had the L33 engine.
Hope this helps you decide which engine your looking for. The LM7 will be the cheapest and easiest to find, so with the money you save from buying the engine. You can have a few more money to swap out the Cam for a Hot Cam to get the added performance your looking for.
hackettsautomotive
New member
Thank you. It helped a lot. I was considering the L33 for the few extra horses.. but when I saw how rare it was, I was leaning toward the LM7...