Reasonably priced BIG BRAKE alternative that fits in a 15” wheel

Ok, what type of spindle? Disc or drum? And what did you use to mount it? Because looking at that caliper I see a whole host of mounting issues. This isn’t to be questioning what you built, but overly complicated mounting that the average guy can’t fabricate without a machine shop isn’t helpful in a backyard situation. a $25 GM truck caliper works with mine also with the benefit of a production 12” over the counter rotor. It’s not about fancy but cost effective and simplicity.

You made a fantastic conversion demonstrating lotsa craftsmanship and skill, that you shared, much respect.
I certainly meant no offense .
I built crap back in the 70s when you did what had to be done to win.
I did back then, - what you did now, used imagination and what was avail/affordable to get the job done. We thought we needed better brakes on our dart, made it so, - but started having the wheel/spindle leave too often.
I graduated to building late-model stocks, then super-modifieds using Camaro front clips and tubing.
I have never had to leave the Mopar family of products for brakes as all needed is made by Mopar, for my needs, - but my experience is available to all .
The full floating pistons avails the caliper to a solid mount .