Discussion Forum - Northstar Chevelle Club

BB502 · Active Member

have auto thinking about stick

Lost in the 60s · President

Do you already have the 4 speed ? If not I would highly recommend considering a NEW M22. 2 reasons....obviously it's new with all new parts that aren't previously stressed and it comes with a warranty. Actually, there are 3 reasons. You can get a few different gear sets internally too. Used Muncies, for the most part, have been hammered on for many years and are tired. One of our members in the club, Steve, rebuilds them and does a VERY good job but the cases are a big concern for stretch and main shaft bore wear resulting in lube leaks. Many times, the cost to bring an old trans back to acceptable standards equals or exceeds the cost of new. Running a 502, I assume your putting significant power thru it too and the new trans are made to handle more torque than the originals.

Beyond the trans itself, you need

correct shifter assembly for year car (key on column needs back drive linkage)

flywheel

pilot bearing in crankshaft

clutch assembly

throw out bearing

clutch fork

bellhousing

pedals

cross shaft (Z bar) and frame tab. Some 502's don't have the provision for the engine pivot ball and you would then need a conversion bracket from Scoggin-D!ckey in TX. I bought one for my '66 with a Gen V bb.

all linkage for clutch to work

If you now have a TH 350 or powerglide, the driveshaft will work as is. If you have a TH 400, you will need a longer driveshaft or have yours rebuilt to the correct length.

Virtually every piece of this conversion is available new, reproduction. Myself, I prefer the look and fit of vintage parts and scrounge swap meets and want ads for them. This takes time and I usually need to "recondition" the linkage pieces because of wear. If you don't want to deal with searching and repairing as necessary, then the all new route might be for you. Of course all new brings a price tag of approximately $3500. Used would be about half that.

The swap itself isn't a huge deal. If you had everything ready, it could be done in a weekend, especially if you had another pair of hands or 2...

Edit note......profanity editor removed the D!ckey name...

-- Edited by Lost in the 60s on Wednesday 6th of April 2011 07:00:42 AM

OscarZ · Treasurer

I was contemplating a similar switch and was going to get the Keisler RS 5 spd conversion kit which comes with everything including driveshaft if I'm remembering correctly. Maybe "someday".

http://www.keislerauto.com/recent-news/keisler-t45-rs-5-speed-for-gm-ford-a-mopar-classic-cars.html

-- Edited by OscarZ on Wednesday 6th of April 2011 04:11:05 PM

SShink · 3K+ Club

Roger,

4 vs. 5 speed depends on how you want the driveline set up and what cruising speeds you'd like to see.

If you are running deep gears (3.55 and deeper) and you are only street/strip, then a 4 speed is fine.

If you run deep gears but still want to get on the highway some, a 5 speed with overdrive is what you want. You can run 3.73's or deeper and still have great performance with decent highway manners.

Keisler has come out with a new 5 speeed/OD that has a slightly smaller case so you don't have to hack/massage the trans tunnel as much as with a Tremec TKO500 or TKO600 trans. I think the whole turnkey kit is around $3K but they are getting popular so the leadtime is moving out. I think Dashboard is looking into this, so he might comment more.

Mitch pretty much nailed the 'what's needed' for a conversion. I've done it on the last 2 Chevelles I've had ('71 and '72), and it is straightforward.

Good luck!

Scott Parkhurst · Super Poster

Or, you could go T56.

It's a factory trans, which helps. I have an LT1 model behind a 383 SB, so I used stock LT bellhousing, slave, throwout, reservoir etc. for the hydraulic clutch. It was pretty easy and with an ATS adapter plate, I was able to hook everything up to a stock (reproduction from OPGI) clutch pedal assy. Centerforce makes the adapter flywheel/clutch setup.

I did have to cut the trans tunnel out of the car from the firewall to the footwells between the rear seats. I had Tin Man Fab (Oak Grove) make the new taller tunnel for me.

The work was worth it. I can now run 3.89:1 gears and still get 20+ mpg on the freeway. It's fun.

The trans I chose is a "Son of Tranzilla" T56 from Rockland Standard Gear (www.rsgear.com). They say it's good to 750 hp- my 383 only makes 545. I've been driving it hard (street/track) for the last 3 yrs now and it's been flawless.

I also added a Hurst shifter and got my driveshaft from Denny's. The modified trans uses a stronger Viper output shaft and I have a Ford 9-inch rear, so the driveshaft had to be all custom anyway.

There are kits for LT1 and LS1-based T56s, and several different companies make good ones (Hurst, Keisler, RS Gear, etc.). But you'll have to modify the tunnel- no question about that.

Chris R · 2K+ Club

Kevin mentioned he was planning to upgrade to this new trans Keisler was coming out with.

Lost in the 60s · President

A better method to install a T56 now is to swap the input shaft to a longer one and use an adaptor plate on a stock 621 bellhousing and all clutch stock linkage. Forget that hydraulic junk. I'm suprised to hear your hydraulic throwout bearing hasn't failed in three years, Scott. A few guys put them in their first gen Camaros a while back and have all now switched to the long shaft and mechanical linkage again.

The new small case T56 should be a huge improvement for guys that don't want to butcher their floor pan.

BB502 · Active Member

Thanks guy's all good things to consider.