I'm guessing you have a stock converter? That "bliping" the gas and slipping into "N" get's old real fast. I had a Crower 3/4 cam at 280D/460L with stock stall converter and if I wasn't in nutral or decelerating, the brakes wre nill.
A vacuum resivour can, fixed that for me. I could have got a higher stall converter and raised my idle speed but the cool "LOPE" of the cam wouldn't have been as profound at 1200 rpm. Besides that, My milage would have sucked as I ran 3:54:1 rears and made monthly 1000mi trips to San Diego from AZ. I still got 16-17 mpg and ran 14's at the track, and several win's at autocrossing. The biggest problem before the resivour was at low speed or at idle when parking. After the first stab on the brakes, the assist went away. Needles to say I've bumped into two cars and lucky me, happened to be friends and not much damage. The thing that was the worst was the "freak out factor" when you stand on them with both feet and it keeps rolling!