haha, to many questions for him. Before i decided to pull the v6, i bored it, put .030 forged pistons, used stock crank, rods. Put a comp cam in, not large enough to mess up the computer, used the roller lifters/pushrods/springs that was recommended for the cam and i used 350 aluminum roller rocker arms. Then, I bought aluminum 4.3 vortec heads, got a 3 angle vavle job, ported and polished. Throttle body spacer, upgrader MAF, and K&N cold air intake. I'm not 100% sure, but i believe i was somewhere around 9.7:1, which means still 87 octane, but i run 92 anyways. But i was getting like 12 mpg city, and like 18/19 highway. My freind put an LS1 in his truck, gets about 16 city and 24 highway. So i yanked the 4.3 and sold it for an undisclosed amount.