here is a pic of a stock plate and manaul brake rod which is 7" long.

you can make a plate and use an adjustable brake rod.

you can use the 2 bolt alum MC that is bolted to the booster.

I have no problems in my 88-440 truck with stopping after converting mine to manaul brakes.

also, I run a hughes whiplash in my 85 stepside which has a 91-318, I run the vac brakes on it with no problems.

only time I have noticed the lower vac on the brakes it was sitting still holding the pedel it seems a little soft sometimes but other than that...it drives like normal as it always did.

IMHO, I would keep the vac booster and run the whiplash. it has very nice street manners,low speed drivabilty is a smooth as stock.. just has the funny car idle.

seems mine likes 8* BTDC and a curb idle of 650-750 rpm.