Inliners International Forums General Discussion Drive Train Manual or Auto for my 55 sedan

I'm in a bit of a muddle.
I can't make up my mind as to what box to run behind my 235 in my 55 sedan. It currently has a 3 speed saginaw on the tree. Problem is it doesn't get good mileage.

I was thinking of a few different combos
3 speed saginaw with overdrive
4 speed saginaw
t5 (but i'm thinking the seat will need to be cut)
th700 but i will have to centre mount my motor

Has anyone done something like this in their 55 before?
Cheers Deano

You won't have to cut the seat with a T-5 if you use a truck tail shaft. It's a bolt on, and is the same length as a regular tail shaft. It moves the shifter forward.
Al

What mileage does it get?
are you sure the speedo is accurate?
What speed do you usually cruise at and what is the rpm?
What is the rearend gear ratio?
What is the outside tire diameter?

Mileage about 18 mpg i think (my old mans 283 gets better mileage)
Speedo is pretty good ( i go buy the tacho anyway)
Cruise at 3000 rpm 60mph
rear end 3:36 or 3:55
Tyre diameter 25 1/2"

So what year truck parts would i be chasing and what t5 would best suit

3000 at 60 mph sounds more like 4.11s but 25 1/2" tires are small. I think there is an input shaft issue with the T5. At any rate if you find a Saganaw 3 speed OD I'd go with that. You could use stock linkage, improve milage, and reduce wear and tear on the engine. The 3 speed OD can be put on a Saganaw 4 speed too but I think there might be linkage problems. ( shifter too far back )

http://www.ringpinion.com/Calc_RPM.aspx


assuming your numbers are right, 3000 @ 60mph and a 25 1/2" tire, would indicate a 3:70 rearend.

Change to a 3:36 and it drops to 2600 @ 60.

That would be the easiest and probably the cheapest thing to to. A 3.08 would drop it a little more, but you may not like driving it around town with it that low.


Next best would be finding a '55-57 3spdOD (car or truck). This would be a direct swap with what you have. Make sure you have all of the peripheral parts to make it work right. I have seen a "parts list" and diagram out on the 'net that explains what to use if the original stuff is not at hand.
A '58-62 may work also, but I'm not sure if the overall length is correct or not.
Newer trans will have a different tailshaft spline count, but could also be made to work.
A 3:70 rearend gear with a 3spdOD is a decent combination.

A T5 is going to be more work and expense than the above options.
Length is different.
Tailshaft spline count is different.
input shaft spline count is different.
To minimize the changes to your car, you would want to look for a '83-87ish T5 from an S10. Most of these had a cable driven speedo (but not all so be aware), and being from an S10, the shifter location should miss the seat, but some heating and bending of the shifter may be required. Shortening/Changing the end of your driveshaft will be required.
You will need a 14 spline clutch disc of the correct diameter. Reuse the rest of the '55 clutch, etc...
Keep the 3:70 rearend.
You will need to trim about 3/8" off the end of the input shaft, and cut the input collar back to the same length as your 3spd.
Be sure to test fit the disc and trans to make sure the splines are long enough to allow the disc to disengage from the flywheel.


After all of this you could see 22mpg or so...

Perhaps a 3:36, HEI ignition, and a Holley Weber carb could get you there with less hassle??...

I have a fireball ignition twin strombergs on a fenton manifold and fenton headers. "I'm pickin up what your puttin down" about the 3 speed and overdrive being easier than a t5 and cheaper (if i can find one here in Oz-straya.

I was just a bit worried about the overdrive part as in solinoids and stuff it seemed a bit complex for me not knowing anything about them.

I would go the 3 speed with an inline shifter on the floor if thats the case

Right. I was thinking that a 3:36 center section would be the easiest of your options to find "down there", so thats what I was focused on, but I did want to go over the other options just in case.

As for the solinoid, there are places that will rebuild them, and NOS parts show up from time to time on Ebay, etc...
I'll see if I can find that website with the info and get back to you...

As for a floor shifter on a 3spdOD, nobody currently makes one. You would need to take a regular 3spd shifter and modify the mounting bracket and linkage to get it to work. I have done this before. Stay away from Sparkomatic and the Hurst Indy shifters, they are not of good quality.
I have seen vintage 3spdOD shifters show up on Ebay, but not very often.

How much do you drive it? Is it your daily transportation, or just a fun car? I would put a Hurst Mastershift or Synchro Loc on the 3 speed and drive it. To me it doesn't make sense to spend $1500 -$2000 to save $150 - $200 in gas a year.

I'll second the Synchro-Loc. Or most any factory installed shifter.

Here's the article I was thinking about
http://www.classictruckshop.com/clubs/earlyburbs/projects/over/drive.htm

Here's one on the 4spdOD conversion that Beater is refering to
http://www.chevytrucks.org/tech/overdrive.htm

I googled "borg warner overdrive solenoid" and found this
http://www.fifthaveinternetgarage.com/parts/parts_counter_3.html


A V8 Camaro/S10 hybrid T5 would be the best way to go in my opinion (with the 3:70 rearend), but also the most expensive option...

Gearhead
i'll hunt down a 3:36 centre and go from there,
as i haven't played with a 3 speed and OD i don't know much about the linkage setup, the only OD type box i've had was in my bush basher 64 crown, that OD kicked in when it hit 40 mph.

(just about to look at the links you posted)

V Stock, the 55 isn't a daily so i see your point
Qusetion whats a Synchro-Loc?

Also can i get synchros for first gear in my standard box and are they hard to fit if i can

A Synchro-Loc is the older Hurst 3 speed shifter that pre-dates the Mastershift. It is a giant step up from the Indy shifter.

A 3spdOD could will still work with the existing column shifter. The front half of the trans looks the same as your original 3spd, even though the parts don't all interchange.

The 3spd didn't get first gear synchronized until the mid sixties, 1964 I think??? not positive.
If you were to go with a mid-late sixties 3spdOD, you would have the first gear synchro, but you would need to do something with the driveshaft yoke.

The Synchro-Loc has "Synchro-Loc" stamped on the side of it for easy identification.

In the process of moving my shop I came across the box for my Hurst shifter. The box says it's a 'Dual-Pattern 3 speed floor shift conversion with Syncro-Loc'.