Stock Brake Proportioning Valve

[TEX-T]

I have a front disk/rear drum setup. I am using the stock proportioning valve that came on a 79 Camero (same as what my rear end came out of). Is okay to use this, or would it be better to use an adjustable proportioning valve like in the brake diagram that Rooster posted awhile back? I am using a 67 Mustang master cylinder.
Thanks,
Tex-T

 

[LumenAl]

I'd use an adjustable... totally different weight distribution, weight, and braking characteristics... IMHO