360 questions

Ok, I wanted to ask because I didn't want to "experiment" with these heads and have the car fall on it's face after 3500rpm or something dumb like that. Like I said, this one isn't going to be a racecar. just a driver but, I want it to run well also. I figure the rear gears that I picked will help. I picked that rear to run because, by the time I get done buying a used 8 3/4 A body axle, I might as well buy a new axle from a company with a warranty for the price I'm going to have invested into 40 year old parts.