If one wanted to help the LP 1275, it wouldn't take moving the earth, or even tearing a engine completely down. I thinking a point more CR, like 12.0 to 1, and more carb liberties, you go to modded HS2, or even have a open carb rule, not like the engine can go faster with more carb than needed, this would allow a racer who did not want to go with the thru bore HS2s to maybe use twin unmodded HS4s, or even a DCOE, just limit how any butterflies you can run to 2, and let those guys figure out what works best.
As for vintage race engines, well believe it or not, that is a much more elevated game, take a look at the gist of vintage race engine, and think how crazy you go with this rule set.
Bore: .047" over same as SCCA
Stroke" stock, same as SCCA
No dry sump unless the car came with it
No crank fire ignition, must use a distributor
Roller rocker arms allowed
Then the all important ending sentence in vintage race engine rules.
All other internal engine components are free.
Now think about that one for a moment compared to SCCA rules.
No ferrous metal rules, use whatever alloys you want, wherever your heart desires
Use the biggest valves you can stick in the head, smaller stem diameters, titanium, its all good.
Want a longer rod, shorter piston, go for it
Billet crank made from anything, got for it, want to get a custom crank, custom rods made, change the journal sizes, after all it all is custom made, got for it. Never thought I see the day when I thought a Moldex crank was low tech, but guess what we are there.
Here's what a vintage race engine components look like these days, it's all sitting in my shop right now, guarded by guys with assault rifles