What type of gear was used in a 1990 f250 3/4 ton with a 4.9 engine?
I recently bought a 1990 f-250 with a 4.9 liter engine. 300 6 cylinder. It is geared really low. (too low) I am running about 3200 rpm at 65 mph and would at least like to get to 65 at 2200 to 2500. The tag on the rear end does not specify the ratio and I am very curious what type of gear I am running, and what type of gear I can replace it with to still get a fair amount of power to work with.
What transmission do you have? If you a direct drive transmission (i.e. non-overdrive automatic or 4 speed manual), it sounds like you have 4.56's. You would be at 3112 rpm's with stock tires. 3.55's or 3.73 will put you the rpm range you want. With 3.55's your rpm's will be at 2423, with 3.73 you will be at 2546 rpm's. Both gears should be alright, but if you do any towing or hauling, the 3.73's would do ya a little better. If you have an overdrive transmission, your down in the 5's. Either way those gears probably not your stock gears.
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