Yes they are...input shaft sizes are different, however, as the Cleveland utilizes the big block input shaft. A Windsor can also run the smaller 10" & 10.5" clutch and 157T flywheel assemblies with the smaller 289/302/5.0 bell housing while the Cleveland can only utilize the larger bell housing for the 11" clutch and 164T flywheel. (The Windosr can also run the 164T flywheel & 11" clutch, but with a smaller input shaft).
When you say "larger" input shaft, what are you referring to? We might be saying different things. I'm speaking of a larger diameter 10-spline shaft with the Cleveland. Do you know its measurements and tooth count?
Yes. Get a Lakewood 5.0 scattershield for the Tremec. Tremec uses the same tranny bolt pattern as the liberty 4spd you have (assuming it's a top loader). If you use the old style bellhousing the throwout arm may not function correctly because the 5.0 uses cable clutch and the old Mustangs used a rod actuated clutch. But as long as you have the correct clutch for your tranny input, you are golden.
yeah i just got the lakewood bellhousing!....when i say larger i mean diamater...i think there are less splines im too lazy to go out to the garage right now lol oh and yes its a toploader...i have two shifters for it a hurst and a vertigade