Good deal, so trans is fine then. The late 70's, early 80's, is when a couple companies started marketing add-on overdrive.
I was part of 4x4 community back then, I had a K20, 3 inch lift, 4.11 gears, with stock 350 and TH400. Same problem. Just getting up to 50mph on the highway and it was screaming.
My Cadillac with a 500 was a better cruiser and got better gas mileage, even though being a 5200 pound beast.
Anyway, going forward you might want to look at a 2004R or 700R4, or maybe 3.08 rear gear.
Rear gear swap might be the quickest and most cost effective.
I was part of 4x4 community back then, I had a K20, 3 inch lift, 4.11 gears, with stock 350 and TH400. Same problem. Just getting up to 50mph on the highway and it was screaming.
My Cadillac with a 500 was a better cruiser and got better gas mileage, even though being a 5200 pound beast.
Anyway, going forward you might want to look at a 2004R or 700R4, or maybe 3.08 rear gear.
Rear gear swap might be the quickest and most cost effective.
