Whats the max amount of cam lift I can use with 1.6 roller tip rockers on stock heads on my 1991 305 TPI engine? also can I use and lt1 cam in my engine?

 

On a stock engine with likely higher mileage on it, pretty much barely above stock. If you plan on making a cam swap, make sure to swap the springs as well. They are no that expensive and can be done with the heads on the engine.

 

ok. How much lift at the valve are the stock heads good for?? and the engine is getting completely rebuilt. Ive heard .520" at the valve is about as much as you can do? also the springs will be swapped along with screw in rocker studs

 

You could get some pretty significant lift, but those heads are junk and wouldn't even come close to flowing anything respectable to match a high lift cam. If you are going for an all out rebuild go 350, putting anything besides basic bolt ons on a 305 is a complete waste of money.