Welcoming your wisdom, experiences & ideas for "reversible" rear-disc upgrade on our '69 Z/28 which we've taken a few reversible liberties with restoration-wise, including Hotchkis springs, Addco swaybars, Fox double-adjustable dampers, Tremec TKO600 5-speed and .640" 253/259 solid roller LT1 with Eagle reciprocating & AFR 210s. The DZ and M20 are tucked away in storage. We take this car for spirited drives on early weekend mornings, and all deviations from original are bolt-in/remove reversible in case the future owner wants to bring the car back to stock. Although we have 17" CCWs for decent handling, I want to retain the ability to drive our 15" Rally wheels sometimes (incl bolting on some 15" drag radials).Thus, we don't want to permanently alter the rear end.
Reasons for the upgrade vs. stock drums with semi-metallic shoes are
(1) May do some track day / DEs next year and figure some non-outrageous 11x1 discs beat the drums' performance/safety window,
(2) I prefer working on discs over drums,
(3) Having 11" discs front/rear seems more "finished" to me / more aesthetically pleasing
(4) Reasonable tradeoff of going F/R 11s with reliable 1-caliper designs for far less money (and performance, clamping force) than exotic JL8 4-piston setup.
That leaves me with the following options which I welcome inputs on plus extra ideas we may have missed somewhere:
The Right Stuff AFXRD05 kit which uses the calipers from T/A WS6, Caddy Seville/Eldo/etc., D152 pads and solid 11x1" rotors, adjusts calipers via parking brake cycling.
Economical ($370-ish) at first blush, but extra costs based on some reviews include...
Requires buying new pads since many reviews had fitment issues with shipped pads that were resolved by installing newer thinner pads) and likely getting their shortened hard-line kit for the axle.
Some installers have noted issues on backing-plate-to-bracket needing to be ground.
Requires you to adjust e-brake then bleed with caliper unbolted & tilted to put bleeder at utmost top.
Increase in track width (due to rotors being thicker than drums) btwn 1/8 to 1/4 inch per side. 1/8" I could live with, but 1/4" may require new rear wheels to get the offset just right with 275s I run back there.
SSBC A125 or W125 (anyone know the difference?) using '87-'88 T-bird Turbo Coupe calipers, D-347 pads and 10.5x1" rotors (adjusts via conventional brake pedal use)
I like this implementation (more conventional adjustment approach) but haven't seen many people using either one of these.
Unknown if their 10.5" rotor hat's cited 0.24" thickness is thinner than TRS AFXRD05's 11" rotor.
$600-$650 street pricing is higher than TRS kit - is the kit easier to install & is it more day-to-day reliable than the TRS kit? I'm willing to spend the extra money if so, and even willing to give up some rotor torque (10.5 vs. 11) if the brake feel & reliability are better.
SSBC A125-30 or W125-30 using proprietary billet 1-piston calipers and 11.25x1" rotors
$950-ish price is approaching my limit, proprietary caliper, unknown pad availability. If there are some people who have had good / bad experiences regarding installation, brake feel, stopping performance & day-to-day reliability, please chime in.
Master Power Brakes Legend kit - hard to tell if it uses same parts as TRS AFXRD05 or SSBC A125 / W125 - any comments? Also open to ideas from similar kits at Matt's Classic Bowties, Pirate Jack's, etc.
Wilwood 140-11398 - 4-piston caliper, internal expanding shoe parking brake, 11" rotor. Beautiful setup, but I lean toward a stock appearance and would feel odd re-painting the calipers to match the front.
Can't afford the Baer kit (which also seems to require 16" wheel minimum), same for Brembo. Not willing to spring for JL-8 kit as I can't even find a price or supply of parts / kit. Not a big fan of CPP's body of work based on neighbor's issues with their suspension & brake parts.
Thanks in advance for additional ideas and for understanding our quirky / reversible scope. Dad bought the Z back in '69, never so much as rolled the fenders, so the next owner will have to decide whether to take it 100% original with our crate of parts, or enjoy driving what's become a very fun-to-drive car similar to the Porsche Outlaw / Petrolicious ethos. Some might consider me a heretic for not replicating yet another Barrett-Jackson garage queen - that's OK. Driving on an early weekend morning is more personally satisfying to me - to each their own.