I purchased four tongue mufflers from stanleyf770's ebay store (he advertises on F@ceb00k as well).
I'm sharing what I've found during fit-checks.
In all, it looks like he's put a lot of work into getting the shapes right! The machining looks good in all but one case.
I've NOT put these on running engines yet; that may come later.
Fox 15
Very nice fit! I have the version in which he cuts away a slot to accommodate the Fox 15 muffler bosses.
12 holes drilled to #51, 0.0670” = 0.042 sq” exhaust area
Fox 35,
Very tight on Fox 35 stunt, can be tapped on. Good fit!
(Does NOT fit Fox Rocket, but then again it's not supposed to, I guess)
19 holes #48, .0760” = 0.0862 sq” exhaust area
McCoy 35 Red Head
Fits McCoy 35 Red Head well.
Also fits McCoy 40 Red Head but needs notch to be cut out of bottom (to clear boss on case)
Des NOT fit older McCoy 36 (too small).
19 holes #48 for .0862 sq”
OS Max 35
He sells this for the "OS MAX 35"; I have a MAX-H. The fit is very tight and should work, but the OS MAX-H 35 has a boss on the case below the stack. The muffler would need a slot ground in to fit.
25 holes at #48 for 0.113 sq”.
On this muffler, one of the side walls is only .045” thick which is too thin for proper set screw thread engagement.
The setscrews are 4-40 with thread pitch of .025”, so there's less than 2 threads engagement. That side will most assuredly strip out. I may try a JB-Weld build up to help support the setscrew.
I'm interested to hear if anyone has actually run these for a while to learn how well the set-screw attachment method works as compared to a strap.