I am looking to purchase a 68 3/4 Truck (87K original miles) and it has a 327/Rochester 4-barrel Quadrajet/Th400 with (as the owner states)3.75 gears. I think that this will not have that good of gas mileage becasue it was used to haul a trailer. I was wondering what would be a good rearend gear to use to get better mileage? I do not plan on making it a daily driver, but with the price I am getting it at, I want to be able to drive and at least have a little peace of mind. It is going to be a project truck for me and my 3 boys. Thoughts and thanks.

 

The 327 engine while a wonderful proformance engine was not famous for mileage. You could go to a 3-40 or even a little higher.You could switch to a 700R4 trans and get overdrive also.