Carbking, I'd be interested in the details on your 68. I'm also working on a 68 gmc. My first mileage check was 15.25 but I found that the choke was not opening completely so I'm hoping to do better on the next tank. I have a 292 with 390 holly 4 bbl and HEI. All the internals of the engine are stock. I have an A833 OD transmission and 3.73 rear gears. It runs about 2000 rpms at 60 mph.
Not a GM - it might be frowned upon if I posted exact details on this forum
But it is a half-ton, with a V-8 somewhat smaller than 400 CID with two Carter 625 CFM carbs running solid linkage producing approximately 450 HP and a 4-speed with granny low.
Will pull from idle to WOT with zero hesitation in 1st, 2nd, and 3rd. Will pull from 1100 to WOT in 4th.
Jon.
