Aluminum master cylinder for 73-80 trucks

[Pyrotechnic]

I wanted to upgrade my 77 to the newer aluminum/plastic master cylinder found in 80's trucks, but I found out there were a lot of differences. One thing is the fact that it wont even fit the booster, the rear part that gets inserted into the booster is larger, meaning you need the newer booster. The other issues is the stepped bore sizes. The bore for the front brakes is larger because of the quick take up feature on the newer calipers, which means you need the newer calipers too. Too much money and work just for the master cylinder.

I searched high and low through the rock auto parts catalog, but it seems like when GM went to quick take up brakes, that's the same time they switched to the new style master cylinder. Every aluminum MC for a GM vehicle seems to be quick take up.

Today I decided to look over in the Ford and Dodge sections to see if there might be something that would fit. I found one for a Dodge D150 that has the correct bore size and correct fitting sizes. The only difference is the push rod depth - GM has a dimple to center the push rod but it looks like the Dodge push rod will seat in about 3/4 inch. There is also the port locations - the rear feeds the front and the front feeds the rear but that can be dealt with.

Assuming that the bolt spacing to bolt up the master cylinder to the booster is the same, I'm thinking that it may be possible to machine a piece of rod with a dimple in it that will fit into the Dodge MC, which will make the push rod area the same as the GM MC.

I may take a trip to OReillys to see if they will bring out both for me check if the mounting bolt pattern is the same.

Has anyone ever done this swap before? What do you guys think? The Dodge MC will be lightweight, won't rust, and has nice screw on caps for the reservoir.

Here's a pic showing both.