3.08 to 3.55 worth it?
- Thread starter Daryl
- Start date
Wmac
Active Member
I agree with sluggish that 3.55 is the most versatile gear. But if you are not going to have forced air, 3.73 is the gear. It will put that hugh smile on your face. If you every go to the track, 3.73 will give you the best #'s. If you get hooked running the numbers ( and its a hell of a lot of fun) be prepared to drop some $ on 31 spline upgrade, d/s loop, tires, etc.
At that point you have become addicted to hotrodding. Its been in my blood for 50 years now.
Daryl; Enjoy your ride. But if you don't have deep pockets, make a wise decision on the rear gear. No sense doing it twice because that now is twice the cost.
At that point you have become addicted to hotrodding. Its been in my blood for 50 years now.
Daryl; Enjoy your ride. But if you don't have deep pockets, make a wise decision on the rear gear. No sense doing it twice because that now is twice the cost.
TrickVert
Active Member
My suggestion for a 5-speed: 3.55's for forced induction, 3.73's if normally aspirated.
sluggish94
Member
I agree. Even in the 1/8th mile I was having to shift into third gear at about the 550-600 ft mark. I couldn't rev any further in second with the 4.10s. With 3.73s I might have been able to rev out 2nd. Experiencing this has led me to understand that one could gear a vehicle specifically to run in the 1/8th or the 1/4. Theres no stopping the addiction once the car runs some times. Always itching to cut the times.
OP
OP
Think I’m going to opt for the 3.55’s when the time comes. I basically just want a little more “umph” off the start (as in traffic signal, not 1/4 mile!) but don’t want to be rolling high rpm’s at highway speeds. I think the 3.73’s would do a number on gas mileage, which is already bad enough at 14-15mpg! And I have a light right foot!
Last edited:
Wmac
Active Member
Your mpg should be much better than what you are telling us. Have you verified that no one has already changed the gears? At 60 mph cruise you should be getting at least 20 & up to 25 mpg
Its easy to do. Block front wheels, lift rear, place chaulk mark on d/s, mark bottom of tire. In neutral turn rear wheel slowly one full turn while counting revolutions on d/s.
308 will be 3 turns of d/s
355 will be 3 & 1/2
373 will be 3 & 3/4
410 will be just over 4
easy peasy.
Its easy to do. Block front wheels, lift rear, place chaulk mark on d/s, mark bottom of tire. In neutral turn rear wheel slowly one full turn while counting revolutions on d/s.
308 will be 3 turns of d/s
355 will be 3 & 1/2
373 will be 3 & 3/4
410 will be just over 4
easy peasy.
My gt with 3:08 and a heavy foot at times still averaged 22-25. I still wonder about your motor.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
Wmac
Active Member
Agree with evil 100%. Next $ should be spent on leakdown test. Somethings not right.
Wmac
Active Member
Driveshaft
OP
OP
Compression low in 2 cylinders
Wmac
Active Member
Think you should spend your $ correcting that issue first.
(off topic. Ask your dad if he ever spent May 24 weekend at the Bend?)
(off topic. Ask your dad if he ever spent May 24 weekend at the Bend?)
OP
OP
Would love to my friend, if he were still with us. I’d give anything to do that.
TrickVert
Active Member
Agreed. Fix the motor, but also, don't worry about the slight RPM difference from 3.55 to 3.75. Remember: You have an O/D transmission. The 100 or so RPM at 60 MPH is negligible.
Check out this RPM Calculator: https://www.cjponyparts.com/resources/engine-rpm-calculator
Check out this RPM Calculator: https://www.cjponyparts.com/resources/engine-rpm-calculator
TrickVert
Active Member
Fourth gear in the T-5 is a 1:1 ratio. Fifth is, IIRC, 0.68:1 Any gear with less than a 1:1 ratio is considered to be an "overdrive" gear.
Last edited:
Wmac
Active Member
5th gear is od in a 5 speed.
Daryl. Sorry for your lose. If your dad was into cars way back when, he was probably at the St Thomas and Grand Bend tracks and like any good canadian, partied hard on May 24 weekend. Beach, booze and girls, plus a dragstrip.
Daryl. Sorry for your lose. If your dad was into cars way back when, he was probably at the St Thomas and Grand Bend tracks and like any good canadian, partied hard on May 24 weekend. Beach, booze and girls, plus a dragstrip.
TrickVert
Active Member
No problem! Everybody has something they don't know (yet). 
