I think the shorter but slightly wider single version is what you want. They made two different boosters: One is a double or tandem booster – primarily for turbo cars (but not exclusively) or the single booster (mostly for non-turbo cars, but, again, not exclusively). Also you want your brakes to be top notch for street driven cars.įor boosters – pretty much anything made in the '80's front wheel drive – but I would shy away from Omni/Horizon parts sense those were not really that much compatible with everything else Chrysler made front wheel drive wise. The problem with driving a car on the streets is too much human error can occur (and not on your end). My opinion for a “performance” car driven on the streets, a brake booster is a necessity. Personally, I think it will be easier to convert to a K-car booster. The good news is if you don't have the power brake assist you are looking for (or lack thereof), then replace with a K-car booster – just as long as you didn't toss any of your old parts (from booster).

The brake lines will need a tad of massaging to get to work - but they will (if not forcing). The holes already exist if going back with cast iron. If making one, I can perform measurements from mine and provide to you.ĭrill new holes into firewall/dash bracket (if converting from a 4-bolt to 2-bolt master cylinder). Make a new firewall stiffening plate (if you can't find one). I do see new/reman manual brake master cylinders for sale from time to time. If you can find a manual brake master cylinder (eBay or other) – get it – for it will have the pushrod already with it. Without one, I would get an adjustable length pushrod (Mancini is good to work with). The rust colored is automatic and Black one is for a manual transmission. There are 6 holes where it goes through the firewall.

This is a late '78-89 under-dash bracket. The holes in firewall or under-dash bracket are not hard to make (if needed). The aluminum brake master cylinder is much preferred over the cast iron version, for several reasons. This is going by memory so there might be more. The differences between the (early) 76-77 (or early '78) and (late) '78 to 89 FMJ master cylinder's (and boosters) are:įirewall holes, Brake booster, Master cylinder, under-dash bracket and the manual brake firewall stiffener plate. Most everything is different, including the holes in the firewall between the 4-bolt (cast iron) and 2-bolt (aluminum) master cylinder versions. If a person is going to used non-factory (aftermarket or Mopar Performance) small block valve covers or going big block – you will have to either remove the power brake booster OR go with a smaller diameter brake booster.Ĭhrysler changed from a 4-bolt cast iron brake master cylinder to an aluminum 2-bolt brake master cylinder in 1978 (mid-year – I think, but it might have been the beginning of model year).

Power brakes to manual brakes