Deac69,
I have about as much in my 292 and overdrive transmission as the lower priced Tremec on the page Bruce posted the link to.
If you don't have to have 5 gears consider a GM MY-6. They were built for GM trucks, 1981-86, and are a 4 speed manual, side loaded shifter transmission. First gear has a 3.09 ratio, 4th gear (overdrive) is .73. It's a large aluminum case transmission that will bolt in directly in place of a 3- or 4-speed saginaw, muncie or Borg and has the very typical GM 10 spline input shaft and fine spline output shaft.
You'll more than likely have to shorten your driveshaft because I believe this box is longer than that huge 4 speed granny box you currently have. Measure twice and cut once.
I've been up in the triple digits a couple of times on the interstate and cruising at 80 turning only 2600 rpms is way cool. On the state highways 60 mph is only 1900 rpms. Hardly even worth shifting into overdrive.
-magic mike-
