M20 4-Speed in 63 C10

[badadrew]

Alright guys - the million dollar question(s)

I'm going to be pulling out the old 230 w/3 on the tree and installing a small block with an M20 4-speed that I have. For those who have done the swap to a 4 speed car trans, I have a few questions.

Will a crossmember for the TH350/400 conversion work? Such as the ones from POL or CPP. If not, are there other options other than fabricating one? (Since I don't turn wrenches for a living anymore, I don't have access to a shop other than my small garage and although I have just about every tool known to man, I never really got into fabrication work so I don't have much along those lines.)

What are the driveshaft options? The truck is a long bed Fleetside but does have a 1 piece driveshaft. Obviously, until I get the trans in, I won't know for sure in terms of length but if someone's already gone this route - what did you use?

In terms of a shifter, I would like to keep the bench seat but suspect that I might run into clearance issues on 2nd & 4th gear unless I get a Hurst that is made for the truck. Since Hurst charges an arm and two legs for the shifter and install kit, I'd rather go with a used/swap meet shifter. The problem is - I don't ever seem to see any used 4 speed truck units. Anyone got some alternate Hurst numbers that will also work?

Thanks in advance and Happy New Year to All!

[62gmc910]

I kept my cast bell housing ,well I used one from a later ('63 on) truck and bolted my Super T 10 to that The M20 is basicly the same trans you just have to use bolts and nuts on the lower two holes. the cast bells clutch fork is far supperior to the pressed steel junk used in aluminum bells

[badadrew]

Are you talking about using the factory bell and leaving the O/E bellhousing crossmember and mounts in place?

I was wondering if that would work but had concerns about not having the aluminum M20 supported by a rear crossmember.

Thanks for the input!

[lakeroadster]

When I bought my truck it had a M20 Muncie 4 speed. No tranny crossmember at all which at first alarmed me. I was all ready to build on.. but I got educated ... check out this link: http://www.stovebolt.com/ubbthreads/...=451242&page=1

As far as the shifter goes mine had a home made chain shifter when I bought it .. weighed about 5 lbs. The shifter was shot so I ended up buying a new hurst shifter set-up for a 57 Chevy with a bench seat. It still was into the bench seat on the C10, so I ended up going with bucket seats. Check out my build thread in my signature. Pictures and more data there.

Hope this helps.....

[62gmc910]

Originally Posted by badadrew

Are you talking about using the factory bell and leaving the O/E bellhousing crossmember and mounts in place?

I was wondering if that would work but had concerns about not having the aluminum M20 supported by a rear crossmember.

Thanks for the input!

Yes
the trans supporting it's own weight is less stress than supporting 1/3 of the engine too

[badadrew]

Thanks John!!!

That was a good read, made sense and reminded me of few things I had long forgotten. I owe you one.

Andrew

[badadrew]

Makes perfect sense - less weight supported by the trans as opposed to front engine mount/rear trans mount only. I would almost think that there would be less stress on the transmission internals as well. With the front/rear mount set-up the stress would seem to be more concentrated on the center where the trans and block mate. With temperature changes and vibration over time I would imagine that there would be minor flex/bend in that area. You might not be able to see or feel it but in some cases a few thousandths of give could bind/misalign the shafts/gears etc...

Very helpfull guys - thanks.

[badadrew]

Now that I've got the mount dilema solved, one more question.

Are there any exhaust clearance issues with the O/E bell set-up and headers?

Or, if you're running headers - what are you running?

[padresag]

Originally Posted by badadrew

Makes perfect sense - less weight supported by the trans as opposed to front engine mount/rear trans mount only. I would almost think that there would be less stress on the transmission internals as well. With the front/rear mount set-up the stress would seem to be more concentrated on the center where the trans and block mate. With temperature changes and vibration over time I would imagine that there would be minor flex/bend in that area. You might not be able to see or feel it but in some cases a few thousandths of give could bind/misalign the shafts/gears etc...

Very helpfull guys - thanks.

it really doesn't make any difference due to stress on any part due to the way or to which position the rear mount is. they did change to rear trans mount in 63 for the automatic and for manuals was it in 67. it has worked both ways for years with no problems
ron

[badadrew]

I wasn't referring to catastophic damage per-say but I saw quite a few issues most people wouldn't expect to have ever been caused by minor mis-alignment/shifting of drivetrain components. I was a tech for many years and a technical specialist/instructor for a vehicle manufacturer for 5 years and you get to see some pretty interesting stuff working with component failure analysis.

[1restorick]

I am real interested in this swap myself. I have a 63 C10 with the original three speed overdrive transmission. I got a Muncie M-20 for free by helping a friend install a Tremec TKO-600 in his 65 C10 stepside. this install was quite the job, but he had a big block with a rear crossmember. Hurst does make a stick that work perfectly with the truck bench seat. Here's a Craigs list ad with a photo of this particular shifter:

http://sfbay.craigslist.org/nby/pts/1525178138.html

I actually have this shifter, however you can still buy the long handle right from Hurst. I Believe that it is part #4331. Not positive, but easily verified. I am wondering if the 63 emergency brake mechanism will clear the shifter mount? I'm also wondering how you can properly route the speedometer cable since most of these transmissions have the attachment on the passenger side. Please take photos when you make this swap.
I agree with many others that the crossmember is not needed. Years ago, I put a 370 HP LT1 in a 55 Chevy along with a Muncie M22 bolted to the stock 55 bellhousing and beat on the car daily until the factory rear scattered the pavement. Happy New Year!!

[badadrew]

That kind of looks like a Hurst #3910002 that I've been looking at. You can see that it would clear a bench as it sits but I wonder if it would hit in 2nd and 4th gears.

On the speedo I'm going to run a programable unit that requires a pulse generator input so I won't be using a cable but you bring up a good point for those who want to run the factory gauges.

[1restorick]

Sir, I was just referring to the four digit part number for the truck shifter handle by itself. Any Competition Plus or Super Shifter assembly for a Muncie could be used with this handle in a truck. I've even contemplated building an overdrive Muncie using the gearset offered by Autogear. Check this out:

Note the gear ratios:

http://www.autogear.net/m22ratios.htm

This guy looks like he builds a nice unit, but pricey:

http://www.m-22.com/m22/m21overdrive.htm

My friend assembled one of these transmissions for a guy with a big block Corvette. It shifted great and the owner loved the option of overdrive without making any serious modifications.

What's make this nice for me is it works with my stock bellhousing and driveshaft.

[badadrew]

That is a nice unit and I agree that it's pricey but with the sale price of just a little over $2600 it's not all that hatefull when you consider what a standard run of the mill M21 is going for right now. It's more than I can spend on mine but if I were in the market for one - I'd give it some serious consideration.

[lakeroadster]

Originally Posted by badadrew

Now that I've got the mount dilema solved, one more question.

Are there any exhaust clearance issues with the O/E bell set-up and headers?

Or, if you're running headers - what are you running?

Headers work with the OEM bell set-up, I have the long tube type on my 65. They need to be tight fitting and hug the rear engine mount though. Unfortunately I don't know what manufacturer made them as they were on the truck when I bought it.

[1restorick]

I've got Hedman Headers on my truck. They fit good with no clearance issues.

[badadrew]

Thanks guys - in less than 24 hours you've saved me both time and money. This is a great forum!

[wrecked36]

Hurst is going to sell the kits, but with a disclaimer that "some modification may have to be made" because these trannys were not put into standard production.

The Street Super/Shifter 4 speed setup you are looking for is Part number 391-0002 for the shifter, and 373-3163 for the install kit. The cross reference number for that install kit is 538-4331. Per the newest catalog they offer.

http://www.hurst-shifters.com/wp-con...atalog_web.pdf

There is also a (probably cheaper and more modification/fab) called the "Indy Universal 4 speed Shifter" PN 391-7535 (cross reference 503-0030) and install kit 373-8616.

Hope that helped. I was bored at work and am going to drop a 1966 283 block backed by a M20 4 spd into my '66 within the next month as well.

Big Jim

[markeb01]

Wrecked36 this is more for your benefit since this is a rather old thread, but if you are going to be doing this install in your 66 in the near future, and if you’re still running the original bench seat – you’ll want to avoid the Street Super/Shifter version and go with the older conventional Hurst Competition Plus 4 speed shifter.

The conventional shifter mounts lower and farther forward on the transmission. With a high hump floor pan, the shifter is completely under the floor. I have the Street Super Shifter in my truck, and the shifter head is up inside the truck, and extends rearward 2-3” beyond the rear end of the removable pan requiring the floor be cut for clearance. The Super Shifter will never clear a bench seat.

The forward mounted shifter may clear a bench seat, especially if the new bolt on 55-57 Chevy shifter handle is used. Recently (and finally) Hurst released a bolt on version:



http://www.summitracing.com/parts/HUU-5388620/

[wrecked36]

Good to know markeb01. Thanks for the insight, once again many dollars and hours saved by the forums.

[wrecked36]

I think I'm going to make something custom out of some thick, flat stock. Not a lot of custom to my truck....the time has come.
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[Solo2002]

im useing this trans in my build to and i was actually thinking of useing a 1 1/8 wrench with the open end cut off of the long sytle wrench the angle of the boxed end seems like it would work out good