Summit Rear disk Conversion Kit.

[tc1959]

https://www.summitracing.com/parts/sum-bk1623
Found this on the El Camino Club Of America Facebook Page, Looks like a nice kit.

 

[MC96]

Allstar and speedway both have the same kit, it uses 93-97 f body rear rotors.

 

[fleming442]

Looks like those blasted, ratcheting Seville calipers, too.

 

[MC96]

Yeah, I would stay away, stick with the 15$ (plus core) metric caliper