We installed our Tremec as an engine/transmission assembly, which makes the install easier, but this procedure is not necessary. Once the install was completed, the benefits were immediately realized. The TKO-500 First gear ratio is lower (than the T-10), so the clutch life will be increased since there is no sliding of the clutch to get rolling. Once we were on the highway, shifting into that extra Fifth gear was a great improvement as the rpm dropped to 2,300 on the tachometer at 72 mph. We would have been cruising at 49 mph with the old T-10 and would have had to bring the rpm up to 3,250 at 72 mph.
Since the install, we are now cruising with the pack on the highways. Previously we would constantly watch the cars go by since we really didn't want to sustain the 3,500 rpm that would be necessary to keep up. As a matter of fact, with the Keisler PerfectFit Transmission and the Holley fuel injection installed in PSA, it's hard to go through a full tank of fuel before stopping for a reststop break. We should be able to go 200,000 miles on our fresh engine since we slowed the rpm down so dramatically. Like we said before, this was a killer win-win!
Here are a couple of quick notes on bellhousing alignment concentricity. The auto service industry never worried much about checking alignment concentricity unless there was a problem with hard shifting, missed shifts, jumping out of gear, or vibration. We've found that most original equipment bellhousings were close enough to concentric to not worry about it. Today we have many choices of aftermarket engine blocks and bellhousings. This proliferation of so many parts increases the opportunity for less-than-satisfactory tolerances. This situation can lead to alignment problems (more than .005). If you want long transmission, clutch, and driveline life, check the bellhousing-to-engine concentricity everytime you mate these two driveline components together.
The latest development in bellhousing alignment is Lakewood's adjustable dowel pins. We wish these high-tech dowel pins were available when we assembled PSA. The Lakewood offset dowel pins allow you to rotate the pin to adjust concentricity, then run a set screw down to lock them in place. If you need to make a change, just loosen the set screw and rotate the offset in the dowel. Lakewood has three: PN15907 (.007 offset), PN15914 (.014 offset) and PN15921 (.021 offset). These pins make the task much easier, and once you've completed one, it's not too bad to do the concentricity adjustments. The extra work pays off in the long run.