Identifying Small Block Trans/Engine Support Brackets

Anyone have any info on the small block trans/engine trans support brackets? Below are some pics of the support brackets. Are there different brackets between 318 and 340? Different from 70 and 71/72+?

Most of them get thrown away as unnecessary.

Yeah I just threw a box of them away last week. I did have some marked as 904 rather than 727 so there must be a difference there. Otherwise I guess I never paid enough attention to them to spot them in the wild.

Why would they bother fitting them unless they performed a function. Seems a bit odd that the bean counters would let them be fitted. Same down under they usually get tossed out especially when fitting extractors.

Ma Mopar had them installed fora reason. Anytime there’s a device mated to the engine to Trans that creates more rigidity can’t be a bad thing.

They were used with automatic transmissions only, not manuals.

So for whatever reason, they felt the extra bracing was needed for them.

I suspect the reasons Ma Mopar installed those brackets on the small block auto trans car was for resistance from breakage. A small block trans is only supported at the top 1/2 of the transmission. The extra brackets were installed on the bottom of the trans bell, giving support all around the bell. With the motor basically supported at the front of the motor, and the trans supported at the back of the trans, the bell to block is the weakest point in the support system, with breakage of the bell the result of a failure. I could see under grueling stress, the lack of support at the bottom of the bell could have been an issue. Since Mopar had the cover all the possible problems, adding the brackets to the small block auto trans was probably a cheap response.
The stick bell is stronger and more importantly, a separate piece from the trans. Should a failure occur, the stick would only require a bell replacement. A failure with an auto trans would result in replacing a complete trans case and swapping the guts into a new case. Gene

That is the exact reason.

4 x 4 trucks broke cases when the brackets were omitted and even 2 wheel drives did when driven off road.

My brother in law had a driveshaft go out of balance at 80 MPH one time, by the time he got it slowed down and to the side of the road, the trans case was busted in several places. Only the torque converter hub kept the trans from falling out! There were chunks of trans case, trans fluid, and an array of other broken stuff that left a trail to the side of the road.
He said he felt a vibration that grew worse very fast, as he hit the brakes hard, he heard a boom, and coasted to a stop on the side of the road. We think he may have lost a u joint, but there was no way of knowing with what was left. Of course, he didn't think he needed to extra brackets on the trans. He has them there now. Gene

318 and 360 brackets are definitely different. I think 360s are longer. Not sure about 340s.

I was able to keep them installed on my 360 with shorty TTI headers. The drivers side just needed a notch cut out of it for collector flange clearance.

Why would the 318 and 360 brackets be different? The engines are the exact same outer dimensions.

I would suspect any difference would be between the 904 trans and the 727 trans, but there may also be differences between the years. One would think that since all the small blocks have the same outer dimensions (except maybe the A motors and the early 273s), all the brackets would mount in the same locations on the blocks, but we are talking about Mopars...
Gene

i seen some broken chevy 4x4 cases before gm retrofitted brackets that bolted to the heavy aluminum flywheel cover they came up with,i wondered if a mount to the frame for those overgrown 203 t cases would have prevented that??

different yrs had mods to them like the notches on the 1s in pics.

some clearance for cooler lines ect..

as far as I have seen they are 904/727 specific sb & BB specific truck & car specific.

I have ditched a lot, had a lot that would not bolt up correctly and have had 1 & 2 installed with headers...most times A-body headers they got ditched.

they come in handy to chop up and make torque straps from engine to frame rail on the cheap.

and I have seen them used on the 4x4 xfers with skid plates to keep from busting the cases.

ma mopar fixed a huge problem on the cheap by stamping out steel trans braces by the thousands.... same as the steering box brace used on late 70s early/mid 80s trucks for cracking frame holes at steering box.

run them if you got them.

I think 340/360 are different as is the 1 motor mount on those blocks due to thicker 4" cyl bore cast blocks..

273/318 LA blocks are same me thinks & you cant bore these 3.91 cyls out to 4" IIRC

318/340 are same stroke but you cant bore a 318 block for a 340 piston

but you can STROKE & BORE a 318 block to a 349 up to a 390 CI

The sides are different but the engine size and 904 to 727 relation are the same. Around 76-77 they moved the little square pad on the engine forward 1 inch on both sides to compensate for the longer starter that they started using, same starter just about half an inch longer than the earlier ones.
So the short ones are early and the long ones are after 76-77 period!

If you run exhaust manifolds, find the correct ones and USE THEM!

Anyone have any photos of their un-restored/restored A-Body with the trans to engine support brackets installed?

Looking to understand color of brackets. It appears the set I have looks to have zinc plating on one and yellow dichromate finishing on the other. Also wanted to know what bolt sizes/lengths were used.