The Stovebolt Site Forums The Shop Area Driveline Trans I should use with a 3.54 posi open rear

I have a 64GMC 3/4 ton that had 4.11 gears in it & at 70mph I was turning 32-3300 rpm. I had 3.53's installed & it dropped to about 27-2800 rpm's.I have a 350 in it so that may make a difference I don't know. Isn't a my6 a 4speed with 4Th as a overdrive & 3rd a 1:1, just use 3rd unless your on the hwy at sufficient speed.