Were the '89-92 1LE F-body front brake calipers the same as the front C4 Corvette "HD" calipers, at the least the ones that don't say "Corvette" on them? From pictures I'm seeing online they look identical, and they apparently take the same brake pads.

 

The two calipers do differ, the banjo bolt location and the width of the bridge, the corvette used a slightly wider or thicker rotor than the camaro

 

As regards the C4 caliper 1988> ,the std version was a 12" rotor ,
the HD J55 option ( std on the '96 model and with the Corvette logo on the GS versions ) was a 13" rotor wider at 1.25"

See
https://www.corvetteactioncenter.com...rakes-640.html

 

the 96 HD 12.99 rotor was 1.1 not 1.25, I use it in my Wilwood FSL kits

 

The standard HD C4 rotor for '88-89 Vettes that Rock Auto sells is about the same thickness as the F-body rotors that they sell for late 80's, early 90's 1LE cars, 1.039" vs. 1.035". seems like the extra .004" wouldn't make much difference in how the caliper fit.

 

Yep that one would fit the 1LE abutment

 

Seems like all these "big brake conversions" are loosely based on how GM did the 1LE, which was basically a conversion from the standard metric set-up they already had. All GM did ,from what I can see, was to hack the original caliper mounting points off of the F-body spindles so they could fit an adapter bracket to it to be able to use the HD Corvette (style) PBR calipers. Then to make the rotor they just took the larger Chevy Caprice/Pick-up rotor and changed to offset of the braking surface on it to line up with what they were left with.

 

My bad , was thinking about my C5 rotors