For anyone interested.
Finally got the SlimLine Inverted Pitts muffler (with smoke chamber) Saturday.
Stock OS muffler with Muffler adapter plate = 10.2 oz.\
SlimLine Inverted Pitts (with Smoke) = 7.3 oz.
Slimline does not use the adapter plate. It bolts directly to the exhaust manifold.

I have burned slightly more than 1 gallon of Cool Power 15% now.

RPM readings with the Slimline were the same as with stock OS with baffle removed. The Slimline seems a little more quiet.

I think I will use the Zinger Pro 20x6 for first flights. I am getting slightly over 7900 rpm now, and lifting 18 lbs, 4 oz on the bench. The Zinger spins up much faster than the APC, and the lower RPM (7900 vrs 9000) is noticeably quiter.

I still need to try a Perry VP-30 pump or the Cline regulator. I am leaning toward the pump. I will need to tap the crankcase for pressure to use either. I talked with Bill at Cline today, and he says to put the regulator between the remote needle valve and carburetor inlet. I'm kind of uncomfortable with that. I have a Perry Pump on my ST 2300 and have had great service and success with that setup.

More later.....