Disc sizing front VS rear, Wildwood etc

[jarhead]

On my 68 Torino i have stock style (brand new) Kelsey Hayes 4 piston 11.3" rotors.

Recently i purchased a Wildwood kit for a 9" that consists of 12.19, 4 piston discs. .890 thousandths smaller on the front...

I will probably sound like a cheap ass asking this...

Will this combo work?

I am trying to cut costs on my spreadsheet, and get this thing done a little sooner. It's already been almost 7 years.

I want to order my Speedtech X-body torque arm, and get humping with this build. Yes I know a X-body is not a Ford, lol... But not a thing on this build is stock, it's kind of Abbie-Normal...

I've already dropped 5K off my spreadsheet...Which is at an insane amount for this build...

The car should weigh in around 3300 without my fat a.. , and has a 427 Dart Windsor style motor expected to push 500/500 at the crank.

OH, and i am set to retire in 4 months, maybe...

Thanks guy's i value the advice.