does anyone know what the part # 13-52-066-923 is when its on a t-5. its not showing anything on the www.5speed.com webpage. thanks

 

That looks like the casting number of the case.

Useless.

"Identifying" a T-5 like that, is only of value if you're doing a Concours restoration or something. If you're trying to buy parts for it, it's either a 87-back, or 88-up. If you need hard parts, you'll also need to know if it's a 6-cyl (14-spline input shaft and VERY WIDE gear ratios); low-perf V8 (26-spline input and better ratios except for the too-high overdrive); or high-perf V8 (26-spline input, the good 1, 2, & 3 ratios, and the sensible overdrive ratio)

 

do you know what wc t-5 has the good gear ratios . t-5 year if possible

 

from what i have seen they are all the same except final drive. you could get a .63 or a .73 final drive. my 89 formula came with the .73 final and finally it started going south so i found a replacement. i later figured out it had a .63 final as its VERY sluggish in 5th.
im currently looking for a .73 final to purchase and will have it installed. a .63 can also hurt your gas milage just the same way as a car with a bigger rear end gear.
a .63 the car will lug along and work the motor requiring it to use more gas just as a car with a big rear gear will burn gas as its high revving. the .73 i found is perfect and since my MPG has sufferd slightly.
i could go from memphis to bowling green on 1 tank, now i hafta stop in nashville to fill up. a little part of that is due to my 305 is slightly cammed up. but it should still do a little better than what it does.

 

so to identify a w/c t-5 you need to count 26 input splines? are there any markings that can help to find out if it is a w/c or not?

 

No.

Early design transmissions for V8 also had 26 splines. As did the better 4-speeds starting in the 60s.

See www.5speeds.com for pictures of what to look at. It's the front countergear bearing.