Hi All

I have been reading the numerous threads about auto to manual conversion, I am considering doing my 76. My question is what trany to use. I do not want to spend a ton of money on a car that is not orginal now, but i just want the fun of a manual. The motor is not stock and to the best of my computer dyno calulations i should be in the 400hp/400tq area give or take, I have 3:08 rear gears. So to start my project what should i start shoping for in a trany. Any help would be great, thanks all.

 

A Richmond 5 speed works great with a 3.08. Otherwise I'd look for a wide ratio muncie.

 

To help narrow the transmission choices down, let's figure out what top gear ratio you would like. What rpm and mph would you like to cruise at? What size tires do you have?

 

wheels are 15" not sure till i get home what is on there for tires, but they are getting replaced. I have a TH400 with 3.08 gears in there now and I turn around 3600 rpm at 65. don't know if it is just the side pipes or just used to new cars with overdrive but it sounds like i need another gear. LOL

 

It's not just the sidepipes.

I'd T56 it, but that's just me.

 

 

It's not the sidepipes man, I've got to make a change or I'm gonna go deaf with my 3.73 and TH350. I'm going to watch this with interest because I am planning to do a Keisler kit 5 speed - but if there's a better way without doing a ton of custom fab work I'm all ears.

Seems to me from what I've read the Keisler kits go in well and their customer service is quite good. Plus, plenty on here have them so no shortage of advice mid conversion should you need it.

 

I love T56s, but unless you are planning to swap the rear gears I wouldnt recommend it. 3.42s make the .50 overdrive in 6th(in a production 94-up T56) nearly useless, and that is with a relatively short sidewall 27540R17. If you are planning a swap to 3.73s or deeper, then the T56 would be a good choice.

 

I've been debating this very same thing and heres what I think:

Ford T5 -
pros: Cheapest 5 speed conversion options, holds up well on mild street driving, good gearing

Cons: Don't ever powershift, will not hold up too long beyond 350hp unless you take it easy on it. Exceptions to the rule are def here on the forum, but average seems to be about right. Also requires a bit of fabrication to get a Ford T5 to work and a lot of Chevys are hard to find and aren't built as strong.

Ford T45
Pros - can find em pretty cheap, good gearing, slightly stronger than t5

Cons - few people have done this swap, all the cons of the t5 and the chevy versions are all from v6's as I can tell.

Ford T-3550, early TKO
Pros: Cheaper than TKO-500 and 600, powershifting not quite as deadly

Cons: Not many have done this conversion, few write-ups on this swap, requires a lot of figuring once you get the trans since there are several versions. Still can have power problems above 400hp.

Oh crap, gotta run, I'll finish this later.

 

3600rpm at 65 it's not correct with 3.08 it should be around
2600rpm at 65, may be you drive in second gear???

3600rpm at 65 you get with 4.11 rear end.
Avner

 

 

Tell me about it.

To the OP if you want to drop your RPM's any lower than you are at now you will need to go with a 5 speed or more. The t-10s and I think the muncies all have a 1:1 final gear in them.

 

You need higher ratio (low #) to lower your RPM if you stay with your trns', also the tier overall height effect the RPM. but every change effect your speedometer readings.

I changed my rear end from 4.11 to 3.36 and reduce the RPM by 650 rev' at 70mph from 3500rpm to 2850rpm but I had to put + 20% adapter on the speedometer to increase the readings to correct value.

You can play with the #'s at this link:
http://www.differentials.com/calc.html

Avner

 

????????? current trans may be slipping ???????

 

When I bought the car last fall the owner showed me a recept for the trany rebuild, it also has a shift kit if that has any efect on anything. I was guesing around 3600 at 65, can't reamber excatly but i know it was in the low to mid 3000 for sure. I did the old count the drive shaft revs to the tire revs and that is how i came up with the 3:08 rear gears, I could be off on that some.

as far as the trany sliping I don't think it is by the rpms when i get on it a little, I think it would be some what noticable but could be wrong.

When they rebuilt the trany could they of done any thing internaly with the gearing to give it lower than 1 to 1 output?? Or do i need to take a closer look at the rear end to get a more accurate ratio figured out?

 

Compare your speedometer reading to other car may be they changed the drive/driven gear of the speedometer in the trns'.
Avner

 

i agree with avner. you either have an incorrect speedo dirve gear (easily changed) or 3.7 or higher gears. next time you're out cruising and you see a radar cop, stop and tell him you want to check the speedo. do a loop past him and find out how accurate the speedo is. i've got 3.55 gears with standard rallys and i turn 3200 at a true 70mph.
jeff

 

You can also check by using a stopwatch and the mile markers on the highway or use a GPS unit.

 

Well, if any of you folks get the summit catalogue, you would find that the tremecs or on sale in there on the first page or so. The T56 is for sale, NEW, for 2,400, or so. They hold up to something like 450hp. Or so the add claims. The gear ratio would make your cruise speeds look something like this.

1st 2nd 3rd 4th 5th 6th
0 0.0 0.0 0.0 0.0 0.0 0.0
500 4.5 6.7 9.2 12.0 16.2 23.9
1000 9.0 13.4 18.4 23.9 32.3 47.8
1500 13.5 20.2 27.6 35.9 48.5 71.8
2000 18.0 26.9 36.8 47.8 64.6 95.7
2500 22.5 33.6 46.0 59.8 80.8 119.6
3000 27.0 40.3 55.2 71.8 97.0 143.5
3500 31.5 47.0 64.4 83.7 113.1 167.4
4000 36.0 53.8 73.6 95.7 129.3 191.4
4500 40.5 60.5 82.8 107.6 145.5 215.3
5000
redline 45.0 67.2 92.0 119.6 161.6 239.2

That's no good. However, with 4.11 gears, it very much ideal. Solution is the TKO 5 speed. Handles more torque, and it hase a more useable gearing for those of us with the 3.08 rear gear. It's alos cheaper, at 1,800. Anyone have any tips or advice, anything at all, at how much fab work it takes to get these to work in an otherwise stock 76'?