Hey everyone im trying to decide what motor im going to build. I have a 5.7 and a 5.3 layingin the garage. Plan on throwing some parts in eiter motor like roating assembly head studs and gaskets. few other bolt ons. Along with a turbo kit. It will be in a extended cab silverado. Which motor would you go with?

 

I would turn the 5.3 into an iron 5.7 and put that in there. The cast iron block will hold up better for what you are doing than the aluminum 5.7 will.