What is the differene between 360 blocks

Trying to summarize a long story. Son bought an '81 Trogan with 360's 2 years ago. Previous owner had "new" long blocks installed. We have been chasing fuel supply and ignition electrical issues, now resolved. Both engines had a few cylinders with low compression. Over the winter, we pulled all heads and did valve job. 2.5 hours running time, oil pressure dropped started knocking. Pulled engine and confirmed. all bearings replaced. Looks like this engine is a '73 i think, and it was punched out .060" oversize. Just about all rod bearing had more than normal wear. Last guy sold a bill of goods and the phone # on his receipt is disconnected. 4 hours of running and the oil pressure slowly dropped to 30 psi @ 3000rpm and we started hearing a slight knock. Totally discussed, we got it to the new marina and put it in the slip on one engine.
My question is, Is an automotive block the same a a marine block? I know freeze plugs should be brass. I'm not concerned with manifolds,starters, heads and such, just the blocks. Since we lost a lot of the season already, he may start looking for a block to build in the mean time.

I don't believe there is much that changes between LM and LA blocks with the same casting numbers. Internals another story.
An article here describes changes with the automotive blocks over the years...…….
http://mopar1.us/sort.html

Some spec on this site that may be useful...…
http://www.mopar1.us/Aengine.html

3 sore spots on small block builds I hear of a lot.

~Oil gallery plug left out (post #2 here)…………
https://www.forabodiesonly.com/mopar/threads/threaded-plugs-in-360la-block.406476/

~Wrong size plug driven into block above rear main cap. Too big and you'll crack the saddle (see oiling section in the spec/casting link above)

~17 foot pound of torque on the 5/16" rocker shaft bolts, not 30 as many manuals state.