Eventually down the road I am looking into twin turboing my 1986 Trans Am. Right now I have the 305 in it. Do you think I should swap out for a 350? 400? Or do you think it'd be fine with the motor I have now if I upgraded it a lot? I figured it'd be about the same price range just to buy a bigger block that way I wouldn't have to put that much more into upgrades. Any sugguestions on what'd be the best way to go about this?

 

Twin turbo means all forged rotating assembly, compression and cam designed for the boost.

Building that engine and not installing the turbos will make it a dog. It might run better than the 305, though.

I'd recommend building it once.

You could build the 305 for the twin turbo, but it would cost you about the same as building a 350. Maybe you'd live longer, though.