result do vary

and I was thinking about 350 hp myself

close enuff

and jumping from a stock 150 hp to 300hp is a big jump IMO,and the 5/16 line is doable

but a 4-v swap to a stock teen is not going to be that much HP to begain with..might bump it to 160 hp

headers have more of a boost than just swaping on a 4-v to a stock 318 in my book