Im running an inverted Porsche G50/52. Pictures are pre shifter and nose cone shortening. I have the nose cone at the machine shop now and can share pictures when it is completed. it should end up about 4" shorter once complete.
Several other Porsche trans-axles will work and are shorter, the G50s are pretty much plug and play with the gear ratios that match well to V-8 torque. The G50/52s were standard with LSD is the reason i chose it. The older G50s have a shorter nose cone and are not quite as strong as the 03s,04,05s,and 52s. is also why I chase the 52.
I didnt do much research on other options such as Audi, etc.
Below is CMS website that has alot of Porsche specs on it. I would suggest looking at gear ratios if you use some of the other transaxles they make.
Type: G50/00, G50/01, G50/02 Original equipment for: Porsche 911 Carrera 1987-1989 Description: H Pattern 5 speed manual transaxle with Borg Warner single cone synchromesh and synchronized reverse Limited Slip Differential: 40% LSD optional equipment Weight (approx): 146lbs Oil Capacity...
I also have a Excel file for a gear speed calculator if you would like it. Its handy to figure ratios to speed and RPM. Unfortunately it doesnt apper that I can upload Excel files here, so if you want it drop me a PM and I can email it to you.