Thanks for the replies guys. Everyone seems very helpful around here! I'll check out the heads when I get home. All I know is that they're 6X and they're from a 350, so I think they're probably 93cc chambers, but I'll check for an ID# when I get home. I have tried no thermostat, 160, and 180, all work about the same. The rear end gear is a 3.55 as far as I can tell (I counted the teeth). I do have a tachometer, though I'm not sure how accurate it is. It looks like an old aftermarket one, and the needle bounces around a lot. I have a TH400 transmission with no external transmission cooler, just the one built into the radiator. The engine RPM at 65mph seems to be around 2800RPM, though it's hard to tell with the tach bouncing between 2500 and 3000. I've read a few places that more water is better (keeps the engine cooler), but maybe this is wrong? I am regretting a little bit not putting in a bigger cam when I had the engine rebuilt. I had a custom-ground RAIV-style cam that I gave to someone for helping me work on the car, but I wanted to make sure I had good vacuum for the brakes, etc. Someday I'll be getting some new aluminum heads and a bigger cam. I just spent about $3500 on the rebuild and some other parts, so not anytime soon I'm afraid. I just don't want to wreck anything by running at 230. Do forged parts offer better protection against heat warpage? I'm also thinking of putting the vinyl top back on this winter and taking care of the minor rust spots found on the roof. I got a quote for $700 to get rid of the rust on top, put the vinyl top on, and replace a few chrome pieces. Does this sound like a good price? Originally the car was silver with a black vinyl top. Right now it's a black hardtop, still having the chrome trim for the vinyl top. What do y'all think of a black car with a black vinyl top? Would that look ok? Ok, getting off-topic now, thanks for the help, any other ideas are always welcome.