I wear ear plugs on track so nothing that's not a problem. The 5 gallon fuel cell limits any sort of "road trip" in it. The A15 in the car now has a moderate cam so it will trundle around the pits and from a stop if you take off in cruise mode it doesn't need the 4500 RPM tire squirming start. The gearing is indeed low 4.38 rear gear and 1-1 top gear with 20.6" diameter Hoosiers.....................4-5K on the highway would be the norm.

Your point about the L series engine is well taken, if it no longer needs to fit a vintage race class then an moderately tuned L-series would be the way to go seeing as it's one of the easiest engine swaps................If I sold the A12 A15 and gearbox that would more than pay for a moderately built L-series motor and 5 speed box. Having put the H190 LSD in the car that would support any L-series motor.

Tom