[jeepguy1948]

The chance that this is the problem is slim but nonetheless I will share it. I was recently asked to sort out a very similar problem on a ‘51 F-1 V8. In the end I found that the owner had installed a new gas cap and it was not venting. A huge vacuum was created and eventually it started to starve for fuel. I would agree with Seth, if the choke cleared it up then clearly a lean fuel issue is the culprit. It could be the carb itself. Is your engine a V8 or the 6. If it’s a V8 and it still has the stock original Holley 94, well, I don’t care for those carbs. The power valve can fail (I don’t know if they have rectified it but for awhile Speedway was selling a rebuild kit that had a bad power valve in it). If the motor has the original ignition it definitely can be a problem, it’s vacuum advance only (no centrifical advance at all) I believe Ford called it the Load-A-Matic. If there is a vacuum leak then you wont get spark advance, it could be the diaphragm on the distributor itself leaking. Many old car guys are too young to remember a points type distributor and the cam in the distributor goes dry and grinds down the rubbing block on the points so that you get more and more dwell, the coil does not build up enough of a charge. That truck has positive ground and I have found many times that the coil is not wired properly. The + terminal on the coil should go to the distributor on positive ground. Let us know how it turns out.