[lthompson05]

Right now I have a pretty faulty, what I believe to be original, 3-speed cruise-o-matic auto transmission on my 66 mustang. I plan on putting in a 5 or 6-speed manual. How much quickness or HP change can I expect?

 

[Cracker289]

Well it shouldn't really affect your horsepower output. As far as quickness, I guess you could say it depends on a lot of factors, but GENERALLY a manual transmission car is about 1/2 second quicker than a similar car with automatic.