Well if that's true, and your brakes are 9", you better leave the slanty in there. Or leave the 318/904 car in the driveway.
65Dartman was being tactful and kind when he said woefully inadequate.
Those 9inchers are good to 30 mph, in a straight line, with the slanty. The 318 will accelerate probably 4 times as fast, and will be up to the speed limit right smartly, and when you find yourself running up some guys tailpipe, those 9s will not slow you down fast enough. Plus when going into a corner just a little too hot, I have busted the ends right off the spindles, and watched the tire roll across 4 lanes of traffic.
Maybe you'll be luckier.
Maybe not.
Wear a helmet and install a 5-point harness.And keep a seatbelt cutter handy.
Or just keep it under 30 mph; and in a straight line.