i'd say a diesel the best/easiest to turbo up... but for some stupid reason nowadays, you almost can't find one worth a darn under $30k

 

I think GEN IV/6L80/GMT-900 always wins given that they are usually cheap enough now used, the 6L80 supposedly can handle a lot of power stock, and you get good heads in 5.3 or 6.2 and a some other stuff. So the GMT-900s have fuel pump control modules? I kind of like fuel pump control modules since you should be able to just change the software and boost the voltage.

 

also the Gen IV rods are a little stronger, i believe.

 

Yes, gmt 900's have fuel pump module so it just needs programming to get fuel flow up. No need for aftermarket fuel system up to 600 rwhp. No need for a boost a pump.