When I first discovered the Scarebird conversions, it made sense to use much more common GM calipers and such, just due to the sheer availability of these things in the aftermarket and salvage yards. Almost everything could be sourced from the local auto supply store . . . almost. So, even for later on with later owners, the knowledgeable mechanics could look and recognize the GM parts and know what they were from. Same with the auto supply people. Rather than some "oddball" Chrysler stuff, from their perspective. So, all of Scarebird's stuff makes sense in that orientation.
The other situation is that we're dealing with hydraulic "leverage", both mechanical with the brake pedal geometry and hydraulic with the size relationships of the master cylinder and caliper piston diameters. So sizes are important!
The power booster issues are important, too. The first time I noticed the need for the dual-diaphragm booster was in a road test of a disc brake Hemi Belvedere, which noted the need for the dual-diaphragm booster. Smaller in OD, but longer with the added diaphragm. In the earlier cars, that OD is important with the limited real estate on the firewall/cowl of the particular cars. It's about the square inch number of the diaphragm per se, I believe, rather than "dual" or "single" diaphragm boosters. I believe the GM initially used some dual-diaphragm boosters on their disc brake vehicles, but later used the single diaphragm boosters with a larger diameter as a matter of course? On some cars, they also had brake pedals with two holes, one for manual brake and the other for power brakes, for the rod attached to the master cylinder/power booster. But, there were some issues with some GM cars running out of boost in certain situations, as I recall. Or "no boost" situations on cold start!
I concur that the BEST situation is Chrysler-designed/built systems! They always seemed to work the best and had the best pedal feel of any cars I've driven, especially "back then". The brakes were always "at the top" of pedal travel, rather than "1/2 way down" in pedal travel (as many GM cars tended to be).
That "Chrysler Standard" was something I missed in the earlier years of my then-new '77 Camaro. The brakes were just not that good, which resulted in one of the "cut-off" situations that resulted in bent sheet metal. They used an organic pad on the outside pad and a metallic one on the inside, to decrease wheel dusting issues (important at the time). I never did like the 9.5" "one side fits many" rear drum size either.
I researched road tests to determine which other GM parts I should look for, but that was inconclusive. I later upgraded the front pads to the COPO '79 Nova police pads and later put '77 Monte Carlo rear drums (same as the '81 Camaro Z/28 export cars and middle '80s Caprice police cars) 11x2 rear brakes on it. THEN, the pedal was "at the top" and it stopped more "like a Chrysler", as I desired. All with the same booster and master cylinder. MUCH more confidence in those brakes, after all of those years and such!
So, use the full-metallic or Carbon Graphite pads on the front, not ceramics. Ceramics are even more abrasive than the metallic ever were. Their added heat resistance is not needed, even for HD use applications on street cars. Ceramics still "dust", just that it's more beige dust than dark gray dust.
Make sure the rear brakes were the widest that'll fit the drums/backing plate combination.
One guy I usually see at some of the cruise-in events locally, we were talking about disc brake upgrades (Wilwood in particular). He mentioned that he did one of those conversions on a Camaro. He liked the way it all worked, but felt that the "one time" ultimate braking power was less than with drum brakes, BUT that it'd stop the same way all day long with the discs (slightly less performance, but consistent at that level).
By observation, some of the aftermarket front disc brake conversion kits just seem a little "less robust" than the factory OEM items. But considering that Wilwood's original heritage was in drag racing, lighter weight is important there. BTAIM.
So . . . OEM-based system parts, the best frictions you can get, correct sizing of hydraulic items, AND bullet-proof installation (with new lines and hoses, one way or another).
CBODY67
