Got a 2002 4.3 4x4 silvirado with 74k...need more power...its also a 5speed...any advice? Wanted to swap in a 5.3?..will it bolt up? What kind of problems would i have..Its paid off and i dont want another payment so gettin another truck is out of the question?
any help??

 

I had a 99 with the sluggish 4.3 v6. I did everything they made for it for performance but it still wasn't enough. The swap is very easy and can be dont in one day if you have all the right parts in front of you. You will need the GM 5.3 frame mounts for your 2002. Make sure you get the corresponding 2wd/4wd mounts. The 5.3 harness plugs right into the factory fuse box and everything works flawlessly. The exhuast bolts right up and everything. The only thing you will need to do is get a 5.3 computer tuned with the VATS taken out and a couple of other things. If you were in my area i would help you do it without hesitation. Let me know if i can help with anything else.

 

i did this exact same swap last summer (except mine's a 99 & has a couple more things to fidget with)

get you a complete engine, harness, & accessories (the alt & PS pump can be reused if you want). for the harness, the cleanest/easiest solution would be to get one from a 4.8/5 spd truck, but you can make the auto trans harness work if need be. swap out the frame & engine mounts, mod your fuel lines, get a V8 clutch, get a new fan shroud (or upgrade to e-fans ), retune your old computer, & you should be good to go. Blackbear did mine & got it on the first try.

also, you'll need new A/C lines to & from the compressor - the rest can be reused. make sure you get the right compressor & lines for your HVAC configuration.


ps - while the engine's out, that'd be the best time to go ahead & do a cam swap, springs, pushrods, & headers... just sayin

 

lots of great info here
http://www.ls1truck.com/forums/v8-conversions/

 

thanks for the reply guys...now i just gotta find a motor and harness...any ideas there???

 

find a yard that just got a 5.3 truck in recently - preferably with the engine still in. i got mine from a tahoe that had the roof smashed & had been there a month & had them pull the motor for me without cutting the harness. if they won't give you the full harness with it, just buy one from a 4.8/5spd. i know Current Performance Wiring can find you one.

 

right on...ill look into it....will i have to change the rad or anything like that...will the fuel pump i have work?

 

you can use the same 28" radiator if you want, but if you can, it'd be worthwhile to upgrade to the 34" with some e-fans (or you can even use LS1 e-fans on the 28"). fuel pump works just fine for me. now if you're gonna be doing lots of mods, bigger injectors, etc, a Walbro would never hurt