1976 Ford F-250

I've recently reinstalled a stock Carter 1 barrel carb on my '76 Ford F250, 300 c.I. 6 cylinder (w/auto trans). The engine runs very well with one exception. When climbing up to freeway speed the engine goes through a sluggish hesitation till about midrange through each gear. As the engine nears normal operating temp the sluggishness decreases some but still is there. As a test I accelerated more aggressively to freeway speed and that makes the hesitation much less but of course driving it that way full time is out of the question. Once cruzing at freeway speed it runs fine. The idle is fine and the electric choke works as it should. The plugs are new and the air filter is new. I checked the vacuum to the distributor and that checks out. Any suggestions will be greatly appreciated.
John McClure
June 12, 2006.

Did you check fuel pump delivery and pressure. I owned a 76 f150 w/ 4 speed manual. I became 1 with that pickup. Best pickup
I ever owned. Let me know if I can help ya.

Big Red
Jun 12, 2006.
Sounds as if you have a fuel restriction problem, an accelerator pump discharge that is not correct, or float level. Be sure the accelerator pump rod is adjusted correctly. You should be able to see steady squirt of fuel into the throttle body when you depress the throttle rod. Be sure your spark plugs have the proper gab about.35. If this does not help, be sure that your timing is correct, & the firing order is correct. Made that mistake myself years ago! Good luck.

Jul 5, 2006.