[keith k]

I did some digging through my computer files, and found that all of the '70 Formula build sheets I have images of show "=*F41 SPC PERF SUSP" on them in the written text fields at the bottom. None of them show anything special on the invoice, though, and they are all 14" wheel cars. So there's clearly no linkage between F41 and 15" wheels. They're also all Van Nuys cars, as Norwood rarely left build sheets in cars in '70. An example of build sheet and associated invoice for a Formula that was on eBay a few years ago are attached.

Also interestingly, every 1970 Trans Am build sheet (also all Van Nuys) also shows "=*F41 SPC PERF SUSP".

In the actual box with the pick code (Box 17 "STAB BAR" at the top center of the sheet), the Formulas all show either FW40, or FW--. The Trans Ams all show either FT40 or FT--.
I'm not sure what those codes mean, but my guess is the text at the bottom that says F41 SPC PERF SUSP was there just to tell the line workers the car needed a rear stabilizer bar (vs standard cars that didn't), but not which bar(s) to put on it.

Official GM specs for stabilizer bars on '70 F Cars:
Trans Am 1-1/4" front, 7/8" rear ...although as has been documented on here, probably half were built with the Formula bars... maybe because the build sheet was confusing!
Formula 1-1/8" front, 5/8" rear
F41 Camaro 1" front, 9/16" rear (so putting F41 Camaro bars on a Formula would actually be a size smaller than standard)

[Formulabruce]

This is probably why my Cousin mentioned the F41 relationship to the Firebirds at Norwood. Chevy did use F41 on 14" tire camaros, 1st gen anyways. I was looking for some correlation for the F41 and 15's on Birds, but What you found Keith makes perfect sense, as far as it can go with the bar confusion. Thanks for posting the info !
I am betting the number of 15" wheel Formulas is pretty low.

[unruhjonny]

To lend some credence to what has been said earlier I just came across this in an article:

The Camaro’s front suspension is a conventional coil-spring arrangement with upper and lower A-arms, ball joints, tubular shock absorbers and a front anti-roll bar. The SS package included heavier springs and stiffer shocks than standard, based on the F41 “special purpose front and rear suspension” option.

https://www.hemmings.com/blog/articl...rolet-camaro-3