I've got a 68 rr chassis drag car. Mustang II front susp. and brakes.
I updated to a GM metric 11 inch rotor and caliper conversion. All went well except for my mushy pedal. I currently have a 21mm bore iron master cyl from a 88 Omni that is floor mounted. I'd like to try a 1 inch bore alum. master that will bolt up to the 88 Omni mounts. Any one know what application or part Number I should be looking for??Thanks Guys

21mm is .8268 dia. try a 95 caravan master which is 24mm[.9449 dia.]wagner # : F108168. this should bolt up. remember, the caravan master does not have a pushrod retainer groove in the piston, so you would need some kind or stop to make sure you can't accidentally pull the rod from the master.
a manual master from a dak pu. is also 24mm and should have a provision in the piston for a retainer ring.[wagner # : F114496-new]
another # is for a 82-87 diplomat w/ 1 1/32"[1.031 dia] bore. wagner # F99294.
i'm assuming you are refering to a "2-bolt" aluminium master. hope this helps.

Yes this does help. Thanks