Anyone running this combo? I've read that 4 wheel discs like the dual diaphragm boosters better. This is what I have on the Firebird at the moment. I originally installed the donor booster/mc from the '80 Trans Am that donated the rear discs, with dual diaphragm and the taller, square mc. I recently upgraded the mc to the '78 Corvette mc, and it feels a bit better yet, probably because I had a slight leak on the old one. But I'd like to go with the single diaphragm booster for a more period correct look, if possible. Anyone running this setup with no issues? I should have about 13-14" of vacuum with the cam I'm running, it made about 15-16" with the bigger 462 I had in the car.

Thanks,

Darren

Nobody runs this setup?

I have on my 59>>
454HO GMPP
4-wheel power disc kit from CPP
7" single diaphram booster
Master w/1" bore
about 17" vacuum

CPP recommends at least 18" vacuum for proper operation.
My 7" single booster booster is not really enough to stop this boat.
(however due to clutch slave & valve cover clearance---I cannot go larger)
The 7" booster (single) provides about 900# of assist (from a tech @ CPP)
A dual diaphram of the same diameter should provide 1100-1200# of assist.

The larger the booster----more assist
and in all sizes a dual diphram, will provide even more.

Now---I just need to get one of the 7" duals to see if this is really true----may even drop to a 7/8" bore in the master for more pressure.

This is as I understand it for the techs @ CPP

Thanks for the reply, Bryan. I'll check the vacuum when I get the new motor together and back in the car, then go from there. I've got the 9" dual booster now, stock from the T/A. It'll definitely haul the car down quick, and never had any issues with vacuum or lack thereof. I just would like the 11" single to get the more correct look under the hood if possible. Just one more thing on my list of "would like to do" stuff. :)

How do ou like those rear discs? I have a set layin around Im thinking about slapping on my nova

How do ou like those rear discs? I have a set layin around Im thinking about slapping on my nova

They work great for me. I know everyone curses the calipers, but I started off with a rebuilt set, and haven't had any issues with them. The one thing you should do is actually use the parking brake, which I'm thinking some people don't, and it leads to issues with the adjusters when they start to wear. They definitely haul the car down to a stop in a hurry, no issues there. :thumbsup:

Using the parking brake on the Caddy calipers is a MUST.

This is how they are kept in adjustment (now, if I would just start using the E-Brake).

Using the parking brake on the Caddy calipers is a MUST.

This is how they are kept in adjustment (now, if I would just start using the E-Brake).


FWIW, if you put the two side by side, the T/A and Caddy calipers are identical. The only real difference is the Caddy calipers come with the brackets and return springs when you buy a rebuilt unit. The T/A calipers, you have to swap the levers and brackets over.

T/A caliper: http://www.partsamerica.com/ProductDetail.aspx?MfrCode=A1C&MfrPartNumber=184141&PartType=5003&PTSet=A

Caddy caliper: http://www.partsamerica.com/ProductDetail.aspx?MfrCode=A1C&MfrPartNumber=18B4510&PartType=5003&PTSet=A