Just an idea.
The accelerator rod, that goes through the floorboard, moves through a thick felt seal.
Remove the seal and test the movement.
If the linkage is free, the rod may be riding against the seal causing significant drag because the rod alignment is not correct.
The link is a picture of a new seal, for reference only.
https://www.ebay.com/itm/122328548165

Last edited by buoymaker; 09/01/2022 5:08 PM.
"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."