Sort of a rookie question I guess, but I’ve never had to find one - all my previous trans’ came with one. I understand I need to know the flywheel diameter, but what beyond that? It’s joining a Muncie M20 with a’74 350 in my ‘57 210 ( I’ve been persuaded to keep the M20 - see my last question for context). Any knowledge is certainly appreciated!
Assuming that you are looking at factory aluminum bellhousings I am thinking that there are two basic units to pick from but the Chevy bellhousing gurus are going to have to elaborate on the differences and how to spot them. From what I remember the "small" one slopes down faster from the flange at the motor to the back while the "Big" for the bigger clutch looks quite a bit bulkier to make room for the larger clutch.
If your using the factory engine mounts you need a 55-57 bell with the mounting pads, or aftermarket safety bell with pads would be best
If you're staying with your '57 front motor mounts you should look for a '55-'57 bellhousing with the ears for the bellhousing side mounts or an aftermarket scattershield with the side mount provisions. If you are going to the later style side engine mounts like the Danchuk conversion, you can use the later aluminum bellhousings. Another consideration is what starter you have. The '57 starter bolts into the bellhousing and the '55-'57 bellhousings have the correct bosses. The later aluminum housings will require the block mounted starter.
The 55-57 will also take a after market mini hi torque block mount with out cutting,or trimming the original starter mount area.The 55-57 is often called a poor mans scatter shield since its not aluminum. If you do go aluminum make sure you dont buy a truck bell housing by mistake.They look like car housings,but have a bigger trans centering hole.They do make a reducer spacer to allow using a car trans,but why not get the correct one the first time.
To answer your question...you can use an aluminum bellhousing casting number ending in 383 or 403 for 10.4" clutches (known as 10.5") or one ending in 621 or 697 for 11" clutches. There is an 11" bell number ends in 444..but that one is pretty big bucks because Corvette guys seek them out. The 697 is exactly the same as far as I can tell as a 621...just used in the mid 70s and probably till '81...those are pretty reasonable as 621s are used by resto guys...697s get overlooked. All the ones I mentioned have their casting number in the same location as the one shown.
That's some good info right there ^^^ now I'm going to look at mine to see what it really is. Thanks BP.
All great info and very much appreciated. So I’m gathering that I can use either the 383 casting, the original tri5 steel, or spring for the Lakewood? I have a 383 local for $40, which is the easiest path - would I need trans side mounts with that? Also found the tri5 housing about an hour away for reasonable price - thinking of that as well. Mounts to the frame horns I imagine? Seems front mounting the newer motor is a limitation I inherited with this project. I suppose moving to side motor mounts at some point might be a good idea? Sent from my iPhone using The H.A.M.B. mobile app
If you put side mounts on the engine, and a crossmember under the rear of the transmission, then you can use a modern bellhousing that does not have the mounting ears. Also, when you or the next person who owns the car gets tired of shifting and goes to an automatic transmission, it becomes a simple swap because the mounts are already set up for it. But there are a lot of other considerations about the way the car is set up...if you want to have an old time hot rod type car, then the original mounting scheme is the way to go. If you want more of a modern street rod flavor, then do the side mounts. we can't see the rest of the car, and we don't know your intent, to offer advise about that.
One other thought if you go with a 55-57 bell housing.A 55-57 has two bolt holes on each side mount surface.Chevy made a truck housing that looks just like it all throught the 60"s,and more than one has been passed off as a 55-57 at swap meets.This housing has one bolt hole,and a locating dowel on each mounting surface.It wont fit a 55-57 as is.You would need a rear trans mount. The casting number on a 55 housing ends in 365.
Thanks again all. My intent is to keep it as “old school hot rod” as possible. As an earlier topic I posted shows, I was contemplating an auto trans, but that’s not really the feel I’m after. Sounds like the original tri5 bell housing is the “right” move at this point unless there’s any additional considerations I’m not aware of. I appreciate all the advice! Sent from my iPhone using The H.A.M.B. mobile app
Just to sum it all up: 1974 Chevy LT9 motor + ‘67 Muncie M20 in a ‘57 Chevy 210 with front motor mounts = cast iron flywheel casting ending in 365? Sent from my iPhone using The H.A.M.B. mobile app
The 74 350 is designed for side mounts, so you don't want to run side mounts with an original 57 bellhousing. While I understand wanting to be "old school", most people opt for side mounts and a rear transmission mount. I think in the long run you will be happier with that type of set up. You need to realize its a long distance from a bellhousing face to the rear end of your car. The trans is hanging in mid air along with the driveshaft. Its an aluminum housing and not the best situation when you have increased the power going thru it by adding 67 cubic inches and probably a 100 more hp. Supporting the trans is a GOOD thing. Later model bellhousings are much more common. Just be sure you get one that has the smaller hole for mounting the trans. Truck housings had larger holes so they don't make your trans align with the crankshaft and WILL cause problems. Also you should indicate the bellhousing hole and possibly buy adjustable offset mounting pins to get it concentric to the crankshaft. The truth is that very few people will pay any attention to whether you have side mounts or original front mounts if the rest of your car has things to catch their attention. Only the hardcore pick flyshit out of pepper group will be all atwitter at noticing that detail............
While the cast iron housing may be strong enough, its the aluminum mounting ears on your transmission that will be at risk. There is a reason why all manufacturers universally went to mounting transmissions on a crossmember. Remember, OEMs never use parts that they can get by without......so there is a reson why they all use trans mounts. Imagine what that trans will go thru if you ever get any wheelhop........
Keep in mind, the clutch cross shaft is partly supported by a bracket that bolts to the stock, Tri-Five bell-housing. The Tri-Five vendors do sell an aftermarket bracket for the cross shaft that also bolts to the later model aluminum bell-housings. Unless your side bell-housing frame mounts have been removed, I'd use a Tri-Five bell-housing , just to keep it easier. You can use a 153 or 168 tooth flywheel, but have to use the matching starter motor, and if you use a full sized, factory type, block mounted starter motor, you will most likely have to remove the lowermost/innermost, bell-housing bolt boss used with the bell-housing mounted, 168 tooth starter motor. I've always used the stock bell-housing, the stock bell-housing mounted starter motor, and the stock style flywheel and clutch assemblies, and I prefer the Borg and Beck style pressure plates. The clutch disc will depend on the splines of the transmission you use. Use whatever motor mounts you prefer, and a rear cross-member if you want one so the transmission does't just "hang" off the bell-housing; I've seen a lot of transmissions with the ears broken off for just that reason (along with "spirited driving"). The ONLY aluminum bell-housing I would ever use, is an old, aftermarket scatter-shield made by Ansen, RC Industries, and a couple of others; none are still legal for NHRA competition, but are a little extra assurance on the street for flywheel/clutch explosions. I am Butch/56sedandelivery.
If you decide to go with a stock cast iron bellhousing these are the two you will likely encounter. The black one is actually a Wedge Engineering scattershield but the side mounts are the same as a stock Chevy. The gold one is from a Chevy truck and uses different side mounts.
There are companies out thee that sell bellhousing adapter mounts that bolt to the later bellhousings to adapt them to '55-'57 Chevys so you can keep your front mounts still. They simply bolt to two bolts on the new bellhousing, and then use the stock frame mounts at the rear. Something else to be very careful on is the bellhousing center hole! Chevy used one for trucks, and a different smaller size for cars. If you get the truck bellhousing the center hole is too large and you'll end up snapping the ears off your 4 speed transmission! The opening needs to be 4.686" and not the larger truck 5.125" size.
Saw this bellhousing for sale here earlier today. https://www.jalopyjournal.com/forum/index.php?threads/1202053/ Center hole may be too large as described above.
If you're wanting to keep the front mounts you will need a tri-5 bellhousing And a 168 tooth flywheel. Also a truck starter, or a bellhousing mounted nosecone on a standard delco-remy starter motor You don't need a rear crossmember for a muncie. First check to see if your block is drilled for front mounts (especially the drivers side) You will need a 4460 fuel pump so the outlet clears the mounts. The reason GM stopped using fr/bell mounts was purely for safety. If a bellhousing mount breaks the engine drops down onto the steering . If you want to add a rear crossmember, then do it properly and convert to side mounts at the same time. Everything will become easier after that. (Fuel pump, Headers etc) Also cut off the rear frame horns where the rear bellhousing mounts attach. Then you can tuck the exhaust up higher A bit extra work now will pay off later.
Picked up an iron tri5 bellhousing today, ends in 922. Fits everything I already have. Figure I’ll also grab a CPP brand crossmember. It’s the same as the Speedway version, but not back-ordered. I think I have this figured out now, thanks again everyone! Now to figure out the z-bar. The clutch pedal rod comes out of the firewall in line with the top of the z... Sent from my iPad using The H.A.M.B. mobile app
Get an assembly manual from any of the Tri=-Five vendors; has just about everything you might need. I am Butch/56sedandelivery.
235 6cyl and 283 V8 linkages are interchangeable on a 57 [including the bracket that bolts onto the bellhousing] The bracket on a 55 is straight and has a narrower "Z" bar. whilst the later years have an offset bracket, requiring a wider Z bar. Just make sure the bracket matches the Z bar https://www.amazon.com/LINKAGE-BRACKET-ADJUSTING-SPRINGS-WASHERS/dp/B01MZ6VO2I
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