Figure the car weights ~3000 lbs. Unless you are going to change the rear axle ratio, in my opinion you do not need an od transmission.
Just for grins, here is a list with transmission gear ratios
http://www.teufert.net/trans/tran-rat.htm Also, here is a high gear rpm calculator for PG/TH350, 200r4 and 700r4:
http://www.700r4.com/speedoCalc/rpmcalc.php
