Takes alot of practice to learn what a car needs.
Epecially a 4 spd.
Alot of newby's have a tendency to wait to long to shift, and go past the engines power band.
Try different shift points and take notes(very important).
Want to shift before engines rev's past peak power.
Even if it rev's to 6000, it may go faster shftf at 5500.
Timing will make a diff also.
Retarding will move power band up.
Advancing will lower it.

Raise rear off of ground and mark tire and driveshaft with chalk.
While turning the tire one full turn, count how many revolutions the drive shaft makes.
Divide the 2. That will get you a close rear end ratio.