Moose440
Member
I have a 1968 Newport and am thinking of switching to a 5spd transmission. Dose anyone know of a conversion kit for the c body. I know silver sports but they don’t have a set up for c bodies. Any help would be great. Thanks
5 speed conversion
- Thread starter Moose440
- Start date
If your car is currently an automatic, the work and cost of such a conversion is going to be lots and much. Finding C Body pedals alone is almost an impossible task. Good luck!
Mudeblue
Well-Known Member
DON'T do it! I have a 66 GTO and the prior owner switched out the 4 speed for a Tremec 5 speed! Terrible, Terrrible mistake. First gear USELESS and to much spread between 4th and 5th. My question, why would you want to go through all that trouble and expense and to gain what?
LocuMob
Fluid Technician with a hat
I'm not saying don't do it, but what's the reason for putting in a 5 speed?
I understand the desire of putting in a five-speed, same reason why my Son and I dropped a 4-speed into the Gremlin, fun! But, the Gremlin was a three-speed, so the pedals were there. Doing the same to an automatic car, especially a C Body, is very impractical to be. Not worth the cost and time.
LocuMob
Fluid Technician with a hat
I was prepared to go that route, install a four speed in an auto car. I found one instead, and now I get to spend 8-10 times as much as if I'd just done the swap!
With the right ratios, a 5 speed would be great.
twostick
Senior Member
The new Tremec TKX is probably the best option for you as far as getting a 5 speed that will physically fit the space. 600 ft/lbs torque rating and a narrower footprint than a T56 or any other aftermarket trans. 2.87 1st gear available.
American Powertrain does some Mopar kits but not likely Cbody specific. If it requires a specific rear crossmember perhaps a B body one could be finessed into position. The part the transmission mounts to should be the same regardless so you would just have to re engineer the ends that connect it to the chassis.
The New TREMEC TKX - American Powertrain
Kevin
American Powertrain does some Mopar kits but not likely Cbody specific. If it requires a specific rear crossmember perhaps a B body one could be finessed into position. The part the transmission mounts to should be the same regardless so you would just have to re engineer the ends that connect it to the chassis.
The New TREMEC TKX - American Powertrain
Kevin
Justin Plant
Well-Known Member
Do some research on a good rear axle ratio for the transmission (and it ratios) you select. Otherwise all the hard work listed above won't be worth it.
73Coupe
Senior Member
Check out Hanlon Motorsports for Tremec trannys and parts: The Tremec 5 & 6 Speed Specialist | Hanlon Motorsports - An Elite Dealer
I'm not sure which version is best but a T5 is probably way too small behind a big block. If you have a 318, then that would be a good choice for starters.
x2 on getting the gears correct - both in the trans and the rear end, otherwise you're wasting your time. I'd say shoot for a gearset that gives you about 12.0:1 overall ratio, at the lowest, in first gear. You could go slightly taller for a engine with more torque, and vice versa for a smaller motor....
I'm not sure which version is best but a T5 is probably way too small behind a big block. If you have a 318, then that would be a good choice for starters.
x2 on getting the gears correct - both in the trans and the rear end, otherwise you're wasting your time. I'd say shoot for a gearset that gives you about 12.0:1 overall ratio, at the lowest, in first gear. You could go slightly taller for a engine with more torque, and vice versa for a smaller motor....
Moose440
Member
So I’m building my car to do more road corse. It’s a 4 door and I already did the motor and the rear I have 3.55 in it and think a stick would be fun. I’m building the car this way because it’s very different and difficult to get one of these cars to handle well.
68 4spd Fury
Senior Member
As stated, the parts for the conversion are rare but do pop up occasionally. Have you considered just the 833 to minimize the mods? If you want an OD, (the 70's-80's 833 OD's had a wide ration spread), but other suppliers, like Passon, have new gear sets that provide the close ratio and still the OD. Just a thought,
73Coupe
Senior Member
Ahhh. Well if you're looking for better handling, a 5-speed won't help.
Moose440
Member
From what I’ve been looking at I’m in between a new 727 with a gear vendors or the tkx there around the same price overall. Maybe a little bit more on the 5speed swap. The only thing is there will be a lot of fab work to put the 5 speed in.
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