Can you use the spindles from a 76 F body to do a disc conversion on a 66-72 B body? If so would I need the upper control arms and lower ball joints from the F body?

Yes, no need to change ball joints or arms. Fits 62 up b bodies. Note though you should use 1970 calipers for this.

For more details look up Mopar Action disc brake swap, covers all the details.

The knuckles will work fine and perhaps the calipers, just depends if you are hanging the calipers to the front or the rear. I'd recommend buying the taller 11.75 caliper adapters and using the 11.75 rotors. B body cars can use all the front brake that you can put on there.

www.DoctorDiff.com will have all the parts you need for the conversion.

Thanks guys!

No problem. There should be a sticky at the top of the page that says "Please view the DoctorDiff website before asking questions about disc brake conversions"!

If I recall correctly there was some controversy in the past over using the F Body spindles over the Mopar Action/Rick Ehrenberg preferred 73-76 A body disc brake spindles, due to geometry issues. But, no one has brought that up, so maybe it is really a non-issue

We ran the taller FMJ knuckles on Tim's red Valiant. 150+ mph at Portland International and lap times competitive with Vipers and Z06 Vettes.

It is a non-issue. We beat it to death back around 2001/2002. E-burg eventually relented that it is not an issue but refused to update his article to reflect the change.

The stated issue was over-angling the upper ball joint. However, I build a 67 Satellite with FMJ spindles and it works fine. I hung the calipers to the rear because of clearance issues and because of that the flex hose routing is opposite from stock. My solution was to make a new hard line mount at the front and add a short piece of brake line from the stock location to terminate the hardline there.