Hello. I have a stock 194 6 in a 3:36 geared Nova wagon. I have added a T5 tranny and found 4th (1:1) RPMs at 2900. OD brings the RPMs to 2088 at 65MPH. I've found this to be too low and bad for mileage. Lately I have been playing with different OD and rear gear ratios on a calculator and changing just the OD from a .72 to a .86 brings the RPMs to 2494 at 65. In addition I tried putting 60 series tires on and changing the rear gears to 3:55s getting 2813. Not much of a difference from the original 1:1 number. Do you think my engine can operate at or just under 2500 and not lose mileage or am I better off with swapping gears and tire sizes? Thanks.
Martin
