Help me figure out what I've got

[txhokie4life]

Picked up a '75 911 RSR Replica

The engine is in pieces. Claim was piston slap. Said to be a 3.8
Owner didn't seem to know much about the engine.

Got it to the shop the other night, went out there tonite to
work on my other race car (924 S Chumps car) and
while I had a moment -- started to take inventory of the RSR engine parts.

Case -- 964-101-111-1R

Tranny -- 950-301-102-3R -- told this was a customized G50/52 with 20/80 LSD

Heads -- 993-105-111-7R

Pistons -- ROSS inside says 100M (100mm?) etched with a serial # 108258A 5
I was told it was a 12.4:1 setup

Cylinder Liner, Mahle H..., 95ZN6 ++++ (what does this mean?) A2 W2

Connecting Rods are said to be Corilla, but I have not confirmed.

Haven't cracked the case yet to see what crankshaft

Also has TWM 3006 Throttle Bodies.

Trying to figure out what I've got and then try to game plan a more reliable engine trying to keep costs reasonable.

thx.

Mike