Technical Mystery Chevy engine adapter - Hydramatic or ??

Hello fella's,

I have had this adapter plate for over 40 years LOL
It bolts to the back of a Chevy engine and looks like might be for adapting an Automatic Tranny of some sort.
Reading the Hydramatic articles recently got my curiosity going
Anyone have any ideas on this ?
It has two weld nuts at the top for bolting the tranny / b'hsg to and one weld nut for a three bolt (Chevy) starter plus a slotted tab right above the starter.

 

Looks to be an early SBC (55-56) starter plate used when installing later model automatic transmissions as there weren't any provisions for a block mounted starter. It mounts between engine block and transmission providing an OEM style mounting surface for the original starter.

 

To me it looks like an adapter to use a BOP turbo behind a Chevrolet and keep the 3 bolt early starter.

 

Of course, the pattern is for the SBC, the BBC, and the 194-292 inline six cylinder engines (probably some of the V-6 engines also), BUT, this is a part that was used specifically with the BIGGER Chevrolet trucks. Why, I don't know, maybe to use an Allison trans or a big manual trans? Anyway, it's nothing special, and not really worth anything; they come up on E-Bay fairly often, and usually, someone will be trying to sell one as an "adapter" for an "XYZ" application. Have't seen one yet that's advertised as coming from a Corvette. I wonder if they actually have more to do with mounting a starter motor than anything? I am Butch/56sedandelivery.

Look up E-Bay item number 254808218584; " GM Chevy 366/427 trudk tall deck engine to transmission adapter plate". $38.75. I am Butch/56sedandelivery.

 

366-454 2 ton truck to Clark 5 speed tran's.

 

^^^^^ https://www.ebay.com/itm/Chevy-engine-to-C60-Clark-5-speed-trans-adapter-366-454-GMC-/124380780199

 

Have had one hanging on the wall for year's. Like to have people guess what it's for.

 

The reason big trucks used this adapter was to mate to the big bell housing necessary for the 197 tooth flywheel and big clutch. They were also used with small blocks, the one I have was behind a 350. As a side note, that flywheel can only be used on engines governed at 4,000 RPM max, preferably 3,800.