My '58 with the original 3-speed has a '73 307 in it. It starts great and moves off the line pretty good but really seems to lag in 2nd and 3rd gear. I push the accelerator and hear the engine open up but it seems to take a few seconds before I feel the truck start kicking in. It gets going plenty fast enough on the freeway so it does'nt seem gas starved. I had the stock? Rochester 2-barrel rebuilt and see gas pumping into the barrels when I push the throttle. Vacuum is good and I used the vacuum gauge to set the carb at idle and the timing which I think is about 10 degrees BTC. My compression seems good with all cylinders at 145-160 lbs. My plugs seem to be burning well, tan, and I bumped up the gap to about.040. I have a aftermarket electronic distributor which I assume works O.K.-it doesn't miss obviously. I once had a slightly hopped up 283 in a truck like this that was much quicker. I wish this truck was a little more responsive to the accelerator. My best guess is just that the carb is a dog. Any other ideas? thanks for any input. Bob