UPDATE! OK, did a compression test and all the cylinders are right around 120 psi. Also noticed that it doesn't do anything until it's been driven for more than 5 minutes. I made my dad take a ride with me in the thing (since he used to work on cars for a living) and the dern thing just would NOT do it. Right up to and beyond 4000 rpm, no trouble until the very last minute. My dad thinks it's the transmission because it only does it when it's warmed up and he thinks it feels like it's just acting up. The transmission IS from '82 and isn't rebuilt... and the motor is fine.... so, think it's the tranny?