Vortec v6 to vortec v8 swap

[Oldg1997]

Hello I'm new here and I'm wanting to swap out my vortec 4.3 to the vortec 5.7 in my 1997 k1500. I have searched numerous websites for info but can't get a for sure answer on what I need. I know I'll have to gather a complete 350, motor mounts, fan shroud, and wiring harness. I will send my PCM to Blackbear for a reflash/tune as well. The truck has the 5 speed in it. Will the trans and clutch work? What about the fuel pump? All of your help is greatly appreciated.

 

[badazzbulldog]

trans and clutch will work you'll need a 5.7 flywheel not sure if the 4.3 one is the same i know it is interchangeable with a 5.0 and not sure on fuel pump

 

[b_faulk75]

Just completed this swap, hit me up with any questions

 

[justincreaser]

did the 4.3 flywheel work on the 5..7?