New guy with a 4 speed wagon

[Bonnewagon]

Most of the old transmissions used an ID system that consisted of rings cut onto the input shaft. A little searching will find them all. The idea is that you want a first gear ratio that compliments the rear gear ratio. It differs for racing, street use, or in-between. I prefer a nice deep first gear so I can take off from a stop without riding the clutch. But not so deep that I can start out in second gear. In my 301 equipped wagon I have the Saginaw with the 3:50 first gear right now with 3:23 rear gears. I still sometimes use it for towing but even around town it is pretty fun set up like that. The 3:11 first with 3:23 rears is pretty much ideal on the street. I used that behind the 400. Saginaw ID chart below.

• No lines on the input shaft- First 2.84, Second 2.01, Third 1.34, Fourth, 1.00
• 1 Line- First 2.54, Second 1.84, Third 1.44, Fourth, 1.00
• 1 Line- First 2.54, Second 1.84, Third 1.32, Fourth, 1.00 <— Much less common
• 2 Line- First 3.11, Second 2.20, Third 1.47, Fourth, 1.00
• 3 Line- First 3.50, Second 2.46, Third 1.65, Fourth, 1.00

Muncies are immensely more complicated with date codes and stuff. But this is a simple chart that covers most. Read this: https://www.ss396.com/cars/complete...MIh-7Bkeb3-gIVFo7ICh1Tow3FEAAYASAAEgIFQvD_BwE Paul Cangialosi is pretty much the manual trans guru and his book is a very good read. The Saginaw is not in it but is probably the easiest to rebuild. I can do one in my sleep and probably have at times. 🙄 And I have never broken one but I do actually drive like an "adult" lately.

The early T-10 is complicated too. Lots of variations. I can't find a simple chart and all the links I found are dead. The Super T-10 is not too hard to ID as they use the rings like the Saginaw.

T10 Second Design (Super T10) 4speed​
Number of ID Groves	1st​	2nd​	3rd​	4th​
2​	2.43​	1.61​	1.23​	1.00​
3​	2.64​	1.75​	1.33​	1.00​
5​	3.42​	2.28​	1.46​	1.00​
6​	2.88​	1.91​	1.33​	1.0​

 

[Mighty]

Awesome thank you Bonnewagon! I remember reading somewhere a few years back (hell it might’ve been on this website) about the lines on the input shaft while I was reading about Saginaw transmissions. I really don’t feel too bad about it now if I’m only going to a couple car shows here and there or cruising on the weekends. The only thing that made me question it was the et street tires I put on. I’d hate to break it on the first 1/4 mile pass after it sat for almost 20 years. Then again I don’t know how much power that small block makes but it’s not a monster by any means. I’d be tickled to run 13’s in it. Also considering putting power steering back on it.

 

[mclellan83]

Welcome, super cool story

 

[Mighty]

Found the original shift knob in a cabinet. I’d almost like to put it back on but I don’t know what I would do with the line lock wire. I’ve never used line locks in my life but Ive seen some decent burn outs

 

[pagrunt]

View attachment 209636Found the original shift knob in a cabinet. I’d almost like to put it back on but I don’t know what I would do with the line lock wire. I’ve never used line locks in my life but Ive seen some decent burn outs

That looks like a older Hurst knob that you can pop out the clear cover & switch out the shift pattern. The OE was black & should of had LIFT by the R as the ITM & OE installed Hurst shifters needed to pull up on the shifter knob to pass the lock out for reverse. If that is the original to the in car shifter then you may have a Hurst Comp Plus shifter inplace of the OE ITM shifter.

 

[Mighty]

Oh wow I didn’t know any of that. That’s the one that was in the car when we got it. I’m glad some of you guys are so knowledgeable about these things! I’ll be nabbing some more pictures before too long

 

[Mighty]

Snagged quite a few pictures of the Muncie and t10. I’ll post some in this thread first but might make a separate thread in the manual transmission section. Here are just a couple that I have.
1. Side view of the Muncie with what appears to be a home made mount towards the tail. Has one line on the input shaft.

2. T10 has a date code on it from 5-29-75.

The t10 had 2 lines on the input shaft. I’ve got more pictures of numbers on each transmission and the input/output shafts etc. didn’t count the number of splines on them but I can do that anytime. Don’t know a thing about these older manual transmissions so I didn’t know if there was something that stuck out on them to where you could say “oh that’s a m20 because of the ________.” Thanks for the time too guys, I appreciate the feedback.

 

[pagrunt]

1. Side view of the Muncie with what appears to be a home made mount towards the tail. Has one line on the input shaft.

By the look of the input shaft that's a '63-'69 M21. But that case cast number & rounded bolt boss says it's a '64 case. Tailhousing is coming back as a '66-'70. Looks like a rebuild with what was handy at the time. Regardless, it's a M21. Your output shaft should have a 27 spline count (used '63-'70) based on the what I see with those cast numbers butt could have the newer 32 spline count ('70-'74) if it's a franken-Muncie with mixed years parts.

 

[ELCAM]

On the muncie I agree with pagrunt it has been repaired or built from parts. There should be a date code where the yellow oval is (P MM DD, P= Muncie, MM =month, DD=day ). Leads me to believe the main case is from the parts counter.

You will have to pull the side cover and count teeth to determine what gear ratios you have.

 

[ELCAM]

The super T 10 is a close ratio (2 grooves on input shaft), you have the date code the top number is a partial VIN from the donor car. the N is for Norwood assy. plant so it can't be from a Vette., That would be S for St Louis. Most likely from a 1975 Z28 or TA.

Your saginaw has more gear ratio on the first gear so you will lose some torque for them burnouts.

Edited to add:
If the muncie has the 27 spline output shaft it will drop in where the saginaw is except the shifter.
The Super T10 will need a 26 spline clutch disc and a 32 spline driveshaft yoke and the shifter to fit your car as it is.