My friend is getting a mustang from his uncle and it is pretty much stock except it has a cat back on it. It is a 5-speed.

My car has a crate 350 bored .030 over, balanced rotating assembly, dual snorkel L69 intake, headers, and i have a BW T10 4 speed.

This is my friends first manual car and i am decent at driving manual. Who do you think would win?

 

What heads and cam does your motor have? It is hard to say without knowing those two critical things. Without it, your motor could make 180hp or 500hp.

 

If the motor was just rebuilt to freshen it up, you will lose. If it was rebuilt and filled with goodies, you have a chance of smoking the guy. It's hard to est. if you don't give all the specs.
At least you have a CI advantage....

 

what year mustang

 

nice 82 T/A.I just saw your link in your sig

 

A 91 LX 5-speed even with all the options and 2.73 gears is probably a mid to high 14s car, so use that as a good point to think from. I would say if you took the time to rebuilt the motor it should make a decent bit of power, but as it sits, the Mustang is easy to guess the 1/4 time with a decent driver, your car we really have no clue!