I have a 79 L-82 with THM 350 and an 3:55 rear. In third gear at redline, which is 6500 RPM, I am at about 110 mph. This is crap! Is there something wrong with my car? According to my top speed spread sheet calculator, with the tires I am using, 255 60R 15, I should get a theoretical top speed of 147 at 6500 RPMs. So WTF, could wind resistance be causing that much of a difference???