Thanks for all the great info so far in this thread. I have learned a lot from everyone.
I am also in the process of swapping in a T5 into my 340 powered 65 Dart. It is a new T5z with a S-10 tailshaft. Got all the parts except the driveshaft. Trying to get some lift time this month to swap it in. The 727 died coming home from CPW's Spring Fling and I'm jonesing to get it back on the road.
It is tough to visualize the the rpm for different transmissions, rearends and tire diameters. I found this calculator very helpful for finalizing setup:
http://www.geocities.com/z_design_studio/. Just enter your trans gear ratios, Rearend ratio, Redline RPM and tire size and you get a good idea of your rpm range.
I finally ended going with a T5z that has 2.95 1st gear with a swapped in a .73 OD to go with my 3.23 rear and 26" tall tires.
In 5th RPM = 1855 @ 60 mph, 2165@70, and 2478@80 mph - should good for highway cruise. Much better than my 727 with a super-loose converter, which ran at around 3800 @ 80mph. First gear should be deep enough (2.95 x 3.23 = 9.5 effective ratio).
This is for a daily driver that will occasionally run at the track. I hope to have this on the road by Labor Day.
Here is what it looks like on the calculator. After you enter in your specific combo just drag the cursor around to different RPMs or Speeds to see the exact RPM.
