I put a B18A1 in my 92 civic. the engine and trans came out of a 92 Integra LS. I went to the tack and got 11 runs in. All range between 17.5 and 15.5 and all had a top speed of 87MPH in 4th gear. My question is, do the gears have a top MPH speed or is that just a by chance I ran the same MPH?

 

just buy a final drive

 

Yes, there'll be a limit dictated by the rev limiter and gear ratio.

 

In any given gear you will eventually hit redline and need to shift. In 4th gear an Integra LS hits redline at about 115 mph. You'll be slightly slower since you have smaller wheels. But 87 mph is nowhere near that. You'd only be at redline in 3rd at that speed.

In general trap speed will be a lot more consistent than ET so I'm not surprised you're hitting the same numbers. Especially if you are shifting into 4th as you cross the finish line.