[67 455 Bird ragtop]

Been rethinking my power brake booster on my project. I was thinking about using a Caddy hydrobooster. But recently have been reconsidering using a vacuum pump for my booster. What booster will give me enough boost for my 4-wheel discs but not cause clearence problems with my tall valve covers on my 67 'Bird?? I've seen a few different sizes on the MP Brake site. They have 9" combos on an overstock sale. They also have 7" dual diaphram units. Any thoughts here? I'd also like a booster that will mount in the stock mounting holes.

Honest dad, that 455 on the side of the block is a serial number

[67 455 Bird ragtop]

Been rethinking my power brake booster on my project. I was thinking about using a Caddy hydrobooster. But recently have been reconsidering using a vacuum pump for my booster. What booster will give me enough boost for my 4-wheel discs but not cause clearence problems with my tall valve covers on my 67 'Bird?? I've seen a few different sizes on the MP Brake site. They have 9" combos on an overstock sale. They also have 7" dual diaphram units. Any thoughts here? I'd also like a booster that will mount in the stock mounting holes.

Honest dad, that 455 on the side of the block is a serial number

[jmax]

I was recently in the same situation, needing more clearance for valve covers on my 69 firebird. I installed the "overstock special" 9" power booster/master cylinder combo from MP Brakes upon reccomendation by their sales/tech staff, but could never get it to work. I went round and round with their tech staff, they just kept telling me I had air in the brake lines. After pushing twelve 32 oz. cans of fluid through the system and speaking with a few different tech personnel, a tech guy said the 1" bore size master cyl that they sent me was the culprit, it didn't produce the volume or pressure required for my disc/drum brakes. They were willing to replace the master cyl, I would just have to pay shipping back and forth. I got really fed up with this combo, pulled it out, and installed a manual master. I sent the booster back to them for a credit towards their manual conversion kit, and although they were willing to replace the power master cyl., they wouldn't take it back for a credit towards the manual conversion kit b/c I had run brake fluid through it! Anyways, the manual conversion kit was complete, bolted right in, and works great. If you deal with MP Brakes, ask to speak to Anwar in tech. He's good.

[tikiklubracing]

I guess MP Brakes is in the business, of going out of business. They must be hardup, and sounds like they are having problems with the cylinders. They try and blame it on bleeding, that always puts it on their, so-called, customers. Sounds like they can't stand behind their product. I'll pass on this Co.

BIGGERISBETTER-78 Catalina, 3650#, 13.567@100.51, 8.613@80.78, 400 .060 .260 domes, 6x8, RPM, 750cfm 4150, 3.73 spool, M&E, Spicer, BOP 8 1/2-10, Stk T-350, CSI, Perma-cool, Canton, scraper, Vit. seal, Summit headers, cam&shks, BMF arms, PAW sht. blk., Dynagear 60#, B7MZgate, Moroso Line lk. 20w50 Valvo. 15 yrs in NHRA tech ret.

[67 455 Bird ragtop]

Ok Thanks for the info on MP. But, will a 9" clear my tall valve covers or should I use a 7" dual diaphram booster??

Honest dad, that 455 on the side of the block is a serial number

[jmax]

I didn't have tall valve covers on at the time, so I'm not sure if they will fit with the 9". However, I can tell you that I only gained about 9/16" additional clearance with the 9" bolted on the firewall. If I remember correctly, their 9" booster measured out to 9 3/8" in diameter overall while my factory 11" measured 10 1/2". (I just went and remeasured the factory booster to be sure.) Hope this info will be of help. Jason

[Brinson Pachar]

My son has a 70 GTO with tall fabricated valve covers. The 9" booster still would not allow us to remove the valve cover without a lot of effort. We installed a 7" dual diaphram unit and it gives plent of clearance. We have drum brakes on the rear though.

77 Formula
9.46 @ 141
8.98 @ 148 NOS

[jmax]

I didn't have tall valve covers on at the time, so I'm not sure if they will fit with the 9". However, I can tell you that I only gained about 9/16" additional clearance with the 9" bolted on the firewall. If I remember correctly, their 9" booster measured out to 9 3/8" in diameter overall while my factory 11" measured 10 1/2". (I just went and remeasured the factory booster to be sure.) So I wasn't getting a full 1" of extra clearance I was hoping for. Another problem I had with their "overstock clearance special" 9" booster was with its mounting brackets. The factory booster brackets made the factory booster/master slope back allowing the pushrod to mount in the lower hole of the brake pedal. The aftermarket 9" brackets made everything sit horizontal which would not allow the pushrod to move far enough down to mount in the lower hole. It would only mount in the top hole of the brake pedal giving too much pedal ratio. As you can tell, my experience with MP's 9" "overstock sale" wasn't good. I'm not saying that they're a bad company or sell bad parts, I'm just trying to give you info you should know. I did install their manual brake conversion kit and am very happy with it. Jason

[STripleduce]

I would go with the dual diaphram as they were originaly designed for low vacuum applications. I use a 7" dual on my '47 with only 7lbs of vacuum and have absolutly no complaints.

http://community.webshots.com/user/stripleduce

[PMDRACER]

I run the dual diaphragm booster from the '78-'87 A/G body car.

TIGER EFI - Electronic Fuel Injection for the Traditional Pontiac Engine. bill@tigerefi.com

The point to life isn't necessarilly the decimal.