Muncie in a 73 bird
 

I know they did not come in 73s but should the Hurst shifter kit for a 70-72 work in a 73 with a M20 muncie?Im saying yes?Tom

It can be done, But this is not my work.

73 TA M22 Hurst

Thanks,figured the tunnel is the same.Tom

Tom, 73, and 74, still had a Muncie M21 HD in it. Fine spline input and a T 400 output shaft, 74 was the last year for the Muncie in a F body.

75 was the first year for a BW, ST10.

The Muncie in the '73 Firebird series was both the M20 (wide ratio, 400 mostly) and M21 (close ratio, 455 mostly).
The Muncie in '74 was the M20 (wide ratio). If PHS states M21, it was the Borg Warner T10 (super or second design).
1970-4 factory Hurst shifter used the same parts, except the mounting plate changed.

Guy has a 73 and wants to put a M20 in it and needs to get the shifter kit.Who ever he is working with does not show a kit for 73 just 70 to 72.Tom

https://www.holley.com/products/driv.../parts/3738605

Camaro kit should work. He should figure out what the transmission came out of first.

Out of a vette,looks like the right mounting location.Tom

Not sure if it helps but I used this B&M shifter on my 77 T/A with a BW ST-10 for a short time. I’m told these were used on Muncies at some point but cannot confirm. The linkage and mounting block appear similar to what is posted above though.

My point being, IF these really were used on Muncies, and it worked on my ST-10 in my 77, perhaps the opposite is true and Hurst will work on the Muncie in a 73. .

a refurbished Hurst off of ebay, Seems a bit high but maybe that is the going price @ ~$900?


https://www.ebay.com/itm/15486324774...0aAgUTEALw_wcB

Refurbished now includes black spray bomb.
Reminds of a restored car with undercoating.

My '73 TA got a factory Muncie. When I bought it back the only vestige of the 4 spd was the clutch pedal zip tied under the dash and the clutch rod boot in the firewall.

GM continued to install the Muncie until Muncie production ended around Dec '73. This was well into the '74 Model Year.

'74 builds initially got the Muncie but began to get the B-W ST-10 as supplies of the Muncie apparently dwindled.

I learned much of this while trying to figure out the correct side cover for my Jan '73 assembled TA. The '73 base TA got the Muncie M21. Back in '78, I remember the TA seemed doggie in 1st. I never knew why but I now wonder if it had to do with the 2.20 1st gear while my GTO at the time had the 2.56.

Because I found it cheap, I have picked up a nice '73 M20 from a Corvette, just by luck essentially date code correct for my TA. So I am happy with it as the car will never be original again.

The correct early '73 TA side cover is 395308 but I discovered that while the 395308 all have a switch boss on both the 1-2 and 3-4 shift lever bosses, only Pontiac used a side cover that employed a TCS switch on the 1-2 shift lever boss. And they only used this arrangement for the early EGR system. Early Pontiac side covers had BOTH switch bosses drilled and tapped and a plug was installed in the 3-4 switch boss. After mid March, Pontiac no longer needed the 1-2 switch boss to be drilled and tapped.

Apparently a lot of Muncie experts are completely unaware of the specific early '73 machining of the 395308 side cover for Pontiac applications. They will tell you that the 395308 side cover 1-2 switch boss was never drilled and tapped.

In researching the side cover usage, I logged the Muncie Assembly dates. The latest one I logged was Nov 5, 1973.

The latest installs of the Muncie happened around April '74 for Camaro and Firebird. I did not try to research Corvettes or other GM Div 4 spd installs in '74.

By April, the ST-10 had already entered production so at least for the Firebird and Camaro, it looks to me that it was hit or miss whether you got one or the other. At first I thought perhaps the Muncie M21 had more of a stockpile and these remained in production for a longer time but Formulabruce posted about his friend's 04C '74 Formula that received an M20. That Muncie was assembled Sept 25, '73 as a '74 trans. Looked to me that this one had collected some dust before it finally found a home as build out of the Muncie inventory came to an end.

Point is, no B-W installs for '73, early '74s still got the Muncie. Starting around Jan '74, they could get either and some time after April '74, it looks like only the B-W was installed.

The '73 Corvette Muncie most likely got the 3952642 side cover. It does not have a 1-2 switch boss so would not work if you want to have the early '73 Pontiac TCS switch set-up.

Even if you find a 395308 side cover, most likely you will have to drill and tap the 1-2 switch boss if you plan to have the early '73 TCS switch set-up.

But installing a Muncie in a '73 auto trans 'bird should be very doable. I agree with Mike, make sure you know the M20 being installed, I'd expect the Hurst shifter that is matched to the trans should work fine.

To each their own, but the eBay shifter would be way over my budget. I completed the purchase of a correct shifter set for a fraction of the eBay one and it suits my needs just fine,

I've yet to find the '73 reverse lock linkage and some other bits. But I keep looking. Good used is all I can afford for stuff so I stay patient.

As I posted, and John V has confirmed, the Muncie was still in 73, and 74 T/As, but it was the HD version with fine spline input, and the same spline, and size as a T400 output shafts. How do I know that? Because back in the day I worked on them, and had friends that owned them.

I also owned a 73 400 G/A with a factory 4 speed, that I bought in 1975 with only 19,000 miles on it. I converted it to a T400 when the clutch went out, because with a 3.23 rear axle, that car was too heavy to keep a clutch in. The factory clutch went out at around 30,000 miles. That also had a HD Muncie, as did a friends 74 T/A with a 400 from the factory. Both cars had the HD Muncie from the factory. It was like a cross between an M22, and a conventional Muncie, I'm pretty sure it had a factory drain plug in it also.

I'm not sure at what point they switched over to ST10s, but by 75 they were all coming with them in them. It may very well been a phase out during the 74 model year.

I guess if you want to believe some printed info over actual experience, that's fine, but I had those cars apart when they were only a few years old, and I know what I took out of them.