Most broken bell housings are because of drive line vibrations or binding from my experience. Guarantee it’s not from cutting the ears off.
My best friend owns a transmission shop, so although I’m not an expert, I’ve played this game quite a bit. I agree with above. Cutting off ears don’t break the bell. It’s from driveline vibrations, in some cases too much power, but it’s an easy fix if it didn’t break the case and just broke the bell. Just get a JW bellhousing. I just asked my buddy and he says the 350 thickness is all the same, “they all break”. I’ve seen this many times, from drag racing
Sounds to me like simple chassis flex. I've broken the bell of a trans before on the street. This was my recipe for broken case: I measured 520lb ft at the flywheel. Multiply that by a 3800 stall, a low gear front planetary (2.76) and then restrain it with a 3.23 rear gear and big sticky wrinkle wall ET Streets, and a crusty stock unibody trying to move 3850lbs. It created a lot of chassis flex. Enough that the guys told me it looked like the whole front end cocked over starboard before the tires even turned. With urethane engine mounts (or solid mounting), most guys will use a stock rubber style trans mount. You stated all your mounts are real stiff urethane-I wouldn't use that for the tail without a cage to help keep a lightweight chassis like yours from twisting up. It sounds like you race it or at least lean on it real hard. Maybe a motor plate with a mid plate is best for you. You can still use urethane to mount the plates to the frame to keep the harshness down on cruises, but using a mid plate instead of a tail mount will eliminate that stress. Technically, you could just go to a urethane mounted mid plate and keep your current engine mounts but you'd miss out on a lot of extra room and clearance in the header area. I'd strongly recommend going mid mount on the trans next time around. -rick
An aftermarket case, or aftermarket bellhousing are much stronger than stock. You might be able to salvage your case with just the bellhousing. But also given the weight and flex that was taken up by the flexplate to converter mounting, it might be wise to not use the old case. You don't necessarily need a full mid plate, you can buy short mid mounts that just bolt on each side and then extend out to the frame, using simple flat rubber pads. Not a full plate style. Just checking also that you have side mounts on the engine? Because if using front mount and then trans tail mount, it definitely needs middle support.
As mentioned you can install some side mounts, You will have to install them between the back of the block and the bell housing. Then you need to have the nose on the convertor extended a 1/4 in where it goes in the crank. Some use a spacer , to each their own. https://www.summitracing.com/parts/...faI13iv-MSaVYg-TlrYBnLi5jcTrr4IQaAi_VEALw_wcB
The Jalopy Journal
