I have a Series 2 ASP 61ABC on a Mac's tuned pipe that is simply awsome in my MW Big Stick. It runs like a raped ape on FAI or 5% fuel and just seems to get better with age, and gives the model unlimited verticals.

I have a ringed 75 which is quite a stump puller too. Sometimes the carb barrels can be a bit coarse but nothing that a dose of emery and some elbow grease can't cure.

The trick to getting the big ones to run well is no or low nitro fuel. Higher nitro fuel most times need an additional head shim to guard against overheating, which can be a problem because of their high comp ratio design.