just to clear something up hear, not all t5s are 10 spline. maybe all fords but i cant say for sure. gm runs a 14 and a 26 spline along with a different bellhousing bolt pattern. infact the t5 in my 41 ford is a 14 spline out of an s 10.
both na and turbo ford 4 banger cars shared the same gear sets. mostly a 3.97 first with earlier ones being 4.03 or 4.02. i dont remember for sure anymore, 4.0something. then the svos in 85 and 86 ran a 3.50 first. v8s were around 3.35 and some ford aftermarket around 2.95. if you search, im pretty sure i posted up a good site with great ford t5 info.
for what its worth, the t5, flywheel and clutch in my pinto is out of an 88 turbo coupe. the bellhousing is out of an 89 (at least im pretty sure, anyhow, it was around that year) fox bodied mustang, as is the tranny mount. i ran my clutch cable straight to the bellcrank without notching the frame or building a bracket. i probably should have, but its been 2 years with no troubles, binding or any more wear than paint being rubbed off my frame. the speedo cable used is one out of an automatic pinto, since the fog speedo cable goes into the opposite side of a t5. my speedo gear is the same that was in the 88 turbo coupe which had 3.55 rear gears. my pinto is still a 3.40 rear gear car and the speedo is off by 4-5 mph.