9in drum brakes

I'm fixing a '66 Valiant for off road (drag) use, with a peppy 360, and I'm determined to at least TRY the 9" front drums (it's a /6 no A/C car). I have some 10" drums/spindles off my '71 Demon that I can upgrade (some) with if it's scary. My '66 Coronet 500 with a 440 stopped pretty damn good with the factory 10x3" drums it came with, and I know it was much heavier than the Valiant. The rearend I'm using in the Valiant is a Ford (uggh, but it's 4.62 geared and spooled) unit from a Maverick that I THINK has 10x2.5" drums, which may help bolster it a little. I may need an adjustable prop. valve, and I'm prepared to add that if needed. There used to be a Super Gas '68 notch Barracuda that ran at tracks near me, and it had a series of progressively meaner 440/451/474/499 engines in it over the years, and the owner kept the 9" brakes!!! He also amazed everyone by running old cast iron Prestolite dual point distributors with only one points set, triggering a MSD7 box. Car was very competitive, and eventually before he sold the car, he temporarily installed a friend's 627" B1TS wedge and a 727 I built with all the A&A goodies and I sold him a 1450 QuickFuel dominator for it. With insane wheelstands and squirrely handling, I think they got a low 5 second 1/8mi time out of it, N/A and with 9" brakes, before the motor got sold to someone in Europe.