Simple Al.How about
Smaller,, Shorter, chain. Might be something to try?
It worked for me at Atwater California 10/53 whereas all the really fast smart guys, were running 11s and 12's. In the 3rd heat I had a half lap lead on Scott Pruitt, he's a fast guy. I mentioned this race a lot, forgive me.
You were geared correctly to take advantage of less torque transfer on the slowest corners allowing the engine to recover better, with the same top axle rpm down the long straights.
The difference with oval racing is there really is no slow corner to gear for that will give you an advantage.
So you must gear to allow the best momentum at the track, at the time.
Stock type 4 cycle industrial engines do not have the over rev potential of the 2 cycle engines you are use to. Oval racing adds the momentum factor. Gearing to take advantage of potential power requires thinking on the opposite end of the spectrum.
What worked in a 2 cycle sprint race which included a tight hairpin or chicane onto a long straight is going to be completely different than what is required on an oval with an rpm limited 4 stroke engine.
Never saw the Atwater course, but bet my description is close.
Situational gearing is what we should be thinking about.
Ratio is a ratio thinking may be wrong for more than just oval racing.