ive got a 331 built for boost and it made 511hp and 615 ft lbs with 9 lbs from a turbo. great motor but like said the stock block is on borrowed time. i know you can cruise around alot of the stang sites and find parts dirt cheap. i would go with the 302 based if its mostly a cruiser,plus blocks and parts are a dime a dozen. ive got a h/c/i on a stock bottom end with all the bolt ons on my 91 and it runs pretty good. theres my 2 cents,lol.