I have the 1 1/32 master cylinder with the first generation viper calipers kit.That is the mc diameter that the instruction sheet suggested when i bought the kit.
I have manual brakes.Although the pressure on the calipers arrives to 1500 psi,the car does not brake well.
Not good brake feeling,the pedal is very hard and i,m not able to lock the wheels.

Searching the forum i have read something about the 15/16" master cyl from Doc Diff.
Will the difference with the 1 1/32" worth the 100$ or more that they ask?

I also have 255 mm diameter drums in the rear with 15/16" wheel cylinders.

Thanks a lot

A quick look online and the master that came on the viper was 1 1/16" but that was also with power assist.

I would drop down to a 7/8" master and see how it feels.

Yes,that is what the sheet said.But as you said,does not work with manual brakes.



What model did use 7/8 MC?

I had found a cheaper dorman 15/16. Cast iron mc for 76'A bodies.The ports are 9/16-18 and 1/2-20.
Are the same than the aluminium master cylinder?
I ask this because i have seen that also were mopar master cilinders with 9/16"-20 threads..

I don't know if any came with a 7/8, you may have to find an aftermarket master from Wilwood, Baer, ssbc, etc.

If the 7/8 is too soft of a pedal or doesn't have enough stroke, then a 15/16 may fit the bill. The problem with all the brake calculations is that it's nearly impossible to calculate actual pedal feel while stopping the car, to know if it's what you want/like; and you end up trying a few different things until you find the perfect combo

searching on the web i have seen the 95' Lebaron uses a 7/8 MC.It uses very different port threads and i cant,t find plug and play adpters for them, so i would need to start fabricating lines, ordering fittings etc.
Besides, i think that the piston back must to be machined to fit the stock pushrod.

I going to try a 15/16 first.If it does not work ,i will go for the 7/8.They are not expensive anyway.

If somebody knows were i could find a 9/16-20 female to 9/16-18 male brake adapter,it would be a big help.

Thanks.

Flaring brake lines is easy. Just cut the flare off, replace the tube nut and reflare