If your truck is a D, AD, W or AW 100/150 that came with factory Power Brakes,

you must identify the style booster on your truck, two styles were available, the Single

Diaphragm booster was large in diameter and sat flat against firewall, it measures

roughly, 11 1/2".  The other version, called a midland or dual diaphragm booster

measured, roughly 8 1/2".  If you are installing a B Engine, 360-383-400, either

booster generally will not cause any value cover interference when using production

style valve covers.  If you are installing a RB Engine, 413-426-440, you must use a

Midland Dual Diaphragm Booster with original Equipment Style Valve Covers. 

Aftermarket or aluminum finned valve covers will not work unless you use the

Midland Dual Diaphragm Booster and relocate booster mounting point, at fire wall,

sometimes as much as 1" further away from engine.

These are easy to install, just unbolt your master cylinder, (no need to loosen lines from

master cylinder.) pull out away from booster.  Then just go inside and remove mounting nuts

from studs and push rod from brake lever.  Reverse Removal procedure for installation.

Since 3/4 & 1 ton Trucks come with heavier duty brakes, they already have a smaller booster.

1972-1978 Brake Boosters are only available in 2 bolt master cylinder styles,

no 4 bolt style boosters available any more.

Over the years we have worked on direct replacements for the

Large Diameter Boosters to the Smaller Boosters:

 Click Here For Big Block Truck Headers & Manifolds

Contact us by E-mail at:  RB@bouchillonperformance.com