Poor brakes for the first 5 minutes

[69 Sleeper Bee]

I would go back to the original style calipers then.
The engineers had it that way for a reason.

 

[Mopars & Missiles]

Thanks for the info M&M, my bad for not explaining myself well.

Cold start (on choke it) idles at 1,200 rpm. Once warm, idle drops to 650-700 rpm. Vac of 15mmHg is at 700rpm idle.

The car was originally a 4 pot front disc / rear drum car. The previous owner swapped the front calipers to an A body single pot calipers because he struggled to find pads for it and costs of pads (silly excuse if you ask me)

Thanks for the additional info! So you do have a pretty normal idle, although vacuum at idle is slightly lower than normal.

Original disc/drum car, although front discs have been changed out from factory Kelsey-Hayes or Bendix 4 piston calipers to a single piston A body type from a different year? Not sure what type A body's used or what year the application was? That info does help us to visualize what is actually going on with your car and brakes.

 

[MoparLeo]

Accurate information always helps to answer questions.

 

[OzCharger69]

and yes the gauges are "cool".

to be honest I also don't think they're cool. They look too modern on the car. They are very practical though. I threw the towel after pulling the gauges out for the fifth time. Oil gauge dies first, then the speedo return spring got unwound, clock died, switches etc etc

I might trying to change the pads first. If that doesn't work I'll go back to DOT 3-4 after an alcohol flush. Thanks all for your input.