T-10/Muncie interchange

[Ed Jennings]

I am working on a 59 that belongs to one of my neighbors. Someone long ago replaced the engine with a 350 and the transmission with a Muncie. The car is a driver, so originality is not a real issue here.

The Muncie which is in the car has both rear mounting ears broken off. One is cracked, the other is MIA. The simple thing, I guess, would be to find a junk Muncie with a good tailshaft housing. Been looking and so far have not found one.

As another alternative, I have a spare 62 vintage T-10 that could be put in the car. It is an iron case version, I presume from a passenger car. I know the output yoke has different splines and would require a new yoke. Any other changes necessary? What about the shifter? It currently has a Hurst shifter, but I don't know what model.
As a side question, will the stock 59-62 shifter fit on a Muncie? I notice the replacement Hurst shifters have different part numbers.
Last, are the input shaft splines the same? I believe they are, but guess it doesn't hurt to ask.

Last question: What about a Super T-10. I know the splines are different, but are there any other fitment issues? :confused:

[Joe L.]

Re: T-10/Muncie interchange

Ed------

Muncie tailshaft housings are not difficult to find. You'll want one with the same casting number as the one that is currently fitted to ensure proper speedo gear position and mounting. Check eBay with a search on "Muncie". Or, call Ed Hartnett or Larry Fischer. Either can get you a serviceable tailshaft housing. Many Muncie tailshaft housings have broken shifter mounting bosses. These work perfectly for late 66+ Corvettes and other Chevrolets since those used crossmember mounted shifters. For these, the shifter mounting fittings on the tailshaft are completely superfluous. Maybe Ed or Larry will take your old tailshaft housing in trade since it can be used for these applications.

A T-10 will be a direct fitment for your application. The original 4 speed trans used for the 59 was a cast iron case T-10. It used a 10 spline input and 16 spline output, The Muncie that you likely have uses a 10 spline input and a 27 spline output (unless you happen to have a 71-74 style Muncie, which I doubt). So, the inputs will likely be the same, but the outputs are different, so a different yoke will be required.

I'm not certain about shifter fitment between Muncie and T-10. However, I believe that the same shifter assembly will fit either Muncie or T-10. For 1963, when both Muncie and T-10 transmissions were used, the shifter assembly was the same for either. So, that strongly implies that the shifters are interchangeable. However, I do think that 1 or more of the shifter rods is different between the 2 transmission types.

The Super T-10 will be a direct bolt in, too. However, it's a little longer than the earlier T-10, uses a 26 spline input, a 32 spline output and the speedo gear fitting may be on the opposite side from what you have. To use it, you would need to use a 26 spline clutch disc, a 32 spline output yoke, and you would need to shorten the dirveshaft a bit. You may also need to use a conversion u-joint depending upon what yoke you use.

If, for some reason, you currently have a 71-74 Muncie installed in the car (doubtful, but possible), then the Super T-10 would be the easiest swap, since most of the conversion mods will already have been necessarily done. You can most easily identify the 71-74 Muncie by the tailshaft housing casting number of 3978764. As I say, I doubt that you'll have that one, but it's possible.

[Ed Jennings]

Re: T-10/Muncie interchange

Thanks, Joe. I had looked on eBay a while back for a housing and didn't see any. Today there are two. Both go off today, and I don't know which, if either is the correct part number. I'll have to get the car back on the lift and get a part number. Incidently, it's not the shifter mounts that are broken, it's the TRANSMISSION mounts. When I drove the car to the shop a few months ago, I noticed a bad driveline vibration starting at about 30 MPH. Thought it might be a bad u-joint since the car had been sitting for several years. When we inspected the driveline it was immediately obvious where the vibration was coming from. The owner said he didn't pay any attention to the vibration "because he thought it was normal". I'll get the part number and see if I can snag one off eBay.