This appears to be another case of layering on uneccessary complexity in the search for reliability resulting in even more problems, cost and complexity.

That engine will run all day upside down with no problems at all 'If' you maintain the proper tank height to spraybar relationship which is carefully spelled out in the OS 120 manual.

I just bought a new one to install in this GP Stearman arf that someone wreaked on its maiden and I rebuilt for myself. Been flying it for about two weeks now(almost every Day) and there are Zero issues with fuel delivery with the tank properly installed and I can and do fly it around upside down a lot even low just because everyone gives me a hard time about flying an old Fordson tractor upside down. They claim it sounds like one too

Properly install the tank and you do not need any pump, regulator and likely even on board glow. I certainly don,t use one of those either.

I have not assembled or flown the CMP Hellcat but have looked one over carefully for someone and there is no reason in that airplane not to put the fuel tank where it should be. The front end is caniverous. CMP cannot be counted on to suggest any fuel tank location at least none that are practical locations In that respect their batting record is even worse than their CG suggestions

Lower your fuel tank down to the recommended height relationship to the needle valve in your manual and it will be as reliable as an old Fordson tractor too and you won,t even need that glow thing.

John