The final drive ratio is the 37/29 primary reduction multiplied by the 58/15 front diff ratio, which comes out at 4.9333.
3.545 is only the rear diff ratio.
As Boofhead has said the gear ratios are correct.
The 1st-2nd Evo steel fork will fit.
The 3rd-4th Evo steel fork will only fit if the gearbox has the 'small hub' slider arrangement. (NRBE type and probably others)
Quite a few GSR 'boxes (NRWE, NQBE to name just two) came with a double syncro 2nd gear and 'big hub' single syncro on 3rd and 4th gear.
The Evo 3rd-4th shift fork will not fit the 'big hub' arrangement.
Double syncros can not be added to a gear that was originally single syncro without extensive machining modifications to the gear.
