Help, dust cap for front brakes

I have 37-41 ford style forged spindles from speedway with the gm brake setup, I can't find dust caps to fit! The ones I have are too shallow, all the parts stores have the same ones, Anybody know what fits it? I need help! My dad goes in for surgery next wednesday and I want him to at least get to drive it up and down the alley before he goes in!

 

Yea, the "directions" should have told you to grind down the spindle snout and redrill the nut hole (save your jokes).

 

I did a few of those swaps years ago and the caps I used were off of early 50's Chevy cars and mid/late 50's Chevy 1/2 ton trucks. Same diameter and very deep. Worked out well.
Max