Hydrobooster with Turbotime block off plate installed.

Hydrobooster with Turbotime block off plate installed.

Hydrobooster with Turbotime block off plate installed.

This is a Wilwood Adjustable proportioning valve. I intend to install this in place of the stock disc/drum prop valve on the truck.
$39.99 + shipping from Summit Racing.

Temp installation.. Will be pulled back off later.

Always something when going custom setup.. This shows gap between old and new booster. There is going to be a plate fabricated to cover this hole very soon.

Instructions that came with hydrobooster and GM parts manual.

This flaring tool is different than standard automotive flaring tools. This one utilizes a 37* flare for connections at the "B" nuts. (Standard auto flares are double flared 45*). Earls had this for $75+ I bought it from summit for like $42 shipped.

X dimension is the length between the firewall fitting and the center of the rod hole in the rod. There is also some change to a larger diameter hole on the Astro booster. The X dimension is 6.125 for the Astro booster, and the SyTy vacuum booster's rod an even 7"..

LS1 Master cylinder & 94 Astro Booster Assy mated together with all pistons, springs, & retainers installed. She's ready to slap up on the firewall !

I chose to clock the booster UPSIDE down to allow for better placement of the fluid lines, they will exit out the bottom now instead of through the TOP.

This shot shows you that the master cylinder line attachments have moved as well.. They were on this side on the SyTy application.

The threaded bolt on the upper RH side was used in place of the stock bolt that came from GM. The '94 Astro piston assy is no longer available from GM, this forced me to use one from a '00 GMC HD truck. Problem is, there is some difference in design apparently, the piston is a little shorter than I needed, hence the replacement bolt.

Part #s for all the parts used.

Hydroboost Booster from 1994 Chevy AstroVan. Napa part # 527333 $183 + $83.33 core. And LS1 Fbody car Master cylinder.

Hydroboost Booster from 1994 Chevy AstroVan. Napa part # 527333 $183 + $83.33 core. And LS1 Fbody car Master cylinder.