Its a good runner. It has lots of get-up-N-go until you get to 45-mph. Then it just loses interest.
It’s a 1983 Ford F-150 King Cab Short Box with a 302? V8, a 5 speed manual transmission, 2 wheel drive & a heavy towing package complete with low speed rear end, over-load springs & a 800 tongue Weight rear bumper. It has about 116,000 miles (long haul miles) on it.
The previous owner said it had had this problem before, and new spark plugs fixed it. I don’t know, but it seems more like a fuel or vacuum problem. It behaves just like one of those rental truck governors. Plenty of power up to a preset RPM, then blah.
A mechanic I know said it may be a RPM limit switch in the transmission that prevents over revving the engine. Is he talking straight? or is he full of it?