Can anyone recommend a suitable firewall mounted master cylinder / brake pedal assembly to install in a 1948 Plymouth?  Manual brakes would be OK, although I wouldn't rule out power brakes.  I plan to retain the original front drums for now, and swap in a Roadrunner 8 3/4 rear with 10 inch drums.  Need to use a firewall mounted unit /removed original M/C to install a new crossmember for a TH350, and it was in the way.  Only a single chamber M/C anyway. Hoping someone has already successfully done this modification.  

I haven't done this yet but I have the same exact question for a 41 Plymouth. My single chamber MC is now located about 2' from the header. I thnink the brake fluid could boil if I don;t move it.