looking to install a hydraulic roller into a LT1 i just bought and am wondering what the limits are on the stock aluminum heads??? i could rebuild heads as well, but am just looking to get about 375 HP and figure i could get away with using everything stock. i plan on porting the heads (mildly) and intake. also is there a good engine management system to buy, or should i find an old harness and computer and have them reworked and programmed?????

You could get 375 out of the heads easily, just remember to change the springs when going to a larger cam.

Best thing, get a stock ECM and harness to use.

also will the throttle body and injectors support the 375-400HP range? if not what sizes should i use???

I don't know if you are doing your own heads or not but try www.eportworks.com He is working on mine I got a "port only" like $400 not bad for someone who knows his stuff. His site also gives you a setup around those hp#'s and his injectors and tb.