Based on the top speed, you're going to need a really tall 1st gear to have any RPM recovery. I'm not sure of how different the pre-unit vs. unit transmission gears are, but to get the 3-4 shift loss below 16% you'll need the close-ratio 24/22 high gear set.
Good point panic,, the std box ratio gap between 3 to 4 is more than the cr, 3rd gear reduction is 1.19:1 for the std.
The close ratio has less reduction and is only 1.09:1 for the 3rd gear but it starts with first gear 1.69:1 which will be tough to take off whereasthe std box first gear has a 2.44:1 reduction.
The wide ratio first is 2.91:1 but that gap between 3 and 4 is huge. wr 3rd is 1.425:1
The 5 speed later unit has a larger gap between 4th and 5th than the close ratio 4 speed (unit and pre unit 4 speeds have the same ratios)
I have both gearboxes.
Excuse my ignorance, but which event(s) are you planning to run at?
thanks,
Frank
The plan is to run SCTA, AMA and FIM