1969 beep beep
Well-Known Member
Hi everyone,
I am currently rebuilding my rear end in my 69 Roadrunner. The car weight is 3900 lbs with no driver. The car is used as a street car, and might see the track once a year. The current motor is a stroker making 600hp 630tq. I am running a 28 inch tire. 60 mph rpm is 2850, with a factory 4 speed. No traction issues with the current 3:91.
I originally had a factory 3:55 with the original 383 engine, and replaced it with a 3:91. I then added the stroker motor. I am in the process of rebuilding the entire car to factory specs. I would still like to keep the stroker motor.
I am thinking of replacing the gear set to either 3:55, 3:73 or keep the 3:91. If I chose the 3:71 it should bring the rpm to 2725 @60 and with the 3:55 it should be around 2600 rpm @60.
Light to light is really great with the 3:91 but after driving on the freeway for 2 hours at 2850-3000 rpm it does getting annoying. The car is usually driven around town and the occasional long road trip.
Any recommendations to which gear set I should stick with? I like the lower rpm with the 3:55 but I don't want it to be a dog out of the hole. I am sure the stroker will help with that. Cam operating rpm range is around 3200-6500. The other question I had was which gear is easier on the drive train components? I am guessing the 3:91.
I am currently rebuilding my rear end in my 69 Roadrunner. The car weight is 3900 lbs with no driver. The car is used as a street car, and might see the track once a year. The current motor is a stroker making 600hp 630tq. I am running a 28 inch tire. 60 mph rpm is 2850, with a factory 4 speed. No traction issues with the current 3:91.
I originally had a factory 3:55 with the original 383 engine, and replaced it with a 3:91. I then added the stroker motor. I am in the process of rebuilding the entire car to factory specs. I would still like to keep the stroker motor.
I am thinking of replacing the gear set to either 3:55, 3:73 or keep the 3:91. If I chose the 3:71 it should bring the rpm to 2725 @60 and with the 3:55 it should be around 2600 rpm @60.
Light to light is really great with the 3:91 but after driving on the freeway for 2 hours at 2850-3000 rpm it does getting annoying. The car is usually driven around town and the occasional long road trip.
Any recommendations to which gear set I should stick with? I like the lower rpm with the 3:55 but I don't want it to be a dog out of the hole. I am sure the stroker will help with that. Cam operating rpm range is around 3200-6500. The other question I had was which gear is easier on the drive train components? I am guessing the 3:91.
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