V6 to V8 swap

[Radio517]

My current truck, a 1998 GMC Sierra, has a Vortec 4.3 in it and I would like to go with a Vortec 5.7 I've looked and haven't been able to find much on the subject. I'm just curious on how hard it would be. If I can get the same mileage, out of a bigger engine, with more power, I might as well. The two are a lot alike from my understanding. Would it require a whole new wire harness? Or do the plugs interchange? I know that I would need a different computer. I'm not sure about the rest. Can anyone give me anymore info or suggestions? Thanks in advance.

 

[superdave]

If you are going to go through the trouble of a swap, you might as well go with an LS swap. The work is going to be about the same.

 

[RyanMerrick]

You won't get the same mileage, but you'll definitely have more power.

http://www.gmt400.com/forum/showthread.php?24795-4-3-to-5-7-swap

http://www.gmt400.com/forum/showthr...ne-Swap-quot-Vortec-4-3L-V6-to-Vortec-5-7L-V8