Nop....no valve needed!

I ran 1/8th mile (6.40's & 6.50's) in a 3200 pound B-body for years with all drum brakes, no booster of course & no prop. valve and never had an ounce of trouble out of it.

"Fat drunk and stupid is no way to go through life son......"

http://www.youtube.com/watch?v=bK-Dqj4fHmM