Thanks, all!
Yep, still at it.
I'd been doing most of the mods since the early '80s at the latest. Very few added since, actually.
About 1991-92 Larry Foster and I contributed several articles to the Cholla Choppers (Tucson) Hanger Talk newsletter on modifying the Fox 35 Stunt.
Larry got real serious about it, contacted Fox Mfg for a large quantity of never-assembled parts to build engines from, hand-matched and modded the best of them, and evolved the L&J Fox. That, being much more generally available, 'allowed me to relax.'
Larry's L&J's do have noticeably more power than my reworks, most of them I've seen shake a little bit more than mine typically do, and they are thirstier. That goes with the increased power. Being made from never factory mangled er, uh, assembled parts, lovingly selected for dimension and fit, Larry's should also serve longer - but has anyone ever really worn out a Fox Stunt except by abusing it?? Larry has also contiued to develop "his" engines, so follow his instructions carefully when you get one.
Why I started reworking Fox 35s is just another aspect of why I am in this hobby. I like doing it! How I did it, for Bill Little and several dozens of others, was to rework the guy's engine. I have never built any on 'spec' for future sale.
Each engine is different, whoever manufactures it. Production tolerances are much better, now, with CAM and improved tooling, even from Fox. (Fox Mfg had a variable reputation for quality in the 1950's/60's'/70's - QC seems much better now, but of course, not up to the standards of precision our better engines display.)
So, the engines I reworked were bought by my 'client' and sent to me to see what I could do with what he got in the box at the LHS or mail-order... I'm glad the basic Fox Stunt is so tolerant of specification spread; a few - and there were a very few - were not suitable for improvement. I told the owner, and sent his engine back intact as I received it.