thewrongguy said:If you got a complete car then the computer and wiring isn't a issue, only things like motor mounts and exhaust. A non-HO 5L probably wouldn't break a 7.5", they make less power then the old pre-8.8" 5L's (1985?). Handling would be crappola, I've been in a 5L with 2.3 suspension, it'll go straight pretty quick, but turning left or right is really scary.
What year is your mustang, what kind of shape is it in, how mechanically inclined are you, 80 bucks can dissappear really quick in labour. And does 80 include gas costs, because if your budget is that small you might need to buy some stickers to make'er quicker.
One unpopular idea might be to sell your mustang and buy a chrysler 2.2 turbo/2.5 Turbo car, those are REALLY cheap to buy/work on. A Daytona IROC-Z (they bought IROC from Chevy, I'm not thinking of camaros!) can be bought pretty easily for less then a grand in private deals (shelby's a little more). They make 150hp, but 200ftlbs at 2000 rpm which isn't too bad for a 2700 pound car. And chrysler put 2.2T/2.5T in everything from cars to trucks to minivans, so parts are cheap and plentiful. I have a video of a 2.2T reliant doing a 10 second quarter mile which is pretty damn cool.
Just throwing out ideas, best of luck
I have a 1988 Mustang LX 2.3, less than 90,000 miles, interior is nice and engine in good running order. I wouldn't dare think of selling it. I love my baby, I just wanna maker her a little faster.