Brake booster/cylinder question

[Supermike]

This may have been asked before, but I couldn't find it...

I'm looking to put a brake booster on my '67, and I really don't have the desire to spend half my Saturday right now driving 25 miles to the nearest pull-a-part to hunt and peck in 20° icy/snowy weather. That's right, I'm a fair weather fan.

That being said, one of the first things I insist on doing to my truck is installing a power brake booster. I can't really afford disc brakes right now (unless I luck into the right parts truck), and for the most part power brakes will slow me down just as quick. And I may soon need to press my truck into service as a daily driver, so timing is a factor too. Power brakes are a must. I can't be taking 100 yards to stop in rush hour traffic.

So I was looking at mpbrakes.com, and noticed they have two combinations of booster/cylinders for our trucks:

FORD TRUCK 7" DUAL DIAPHRAGM POWER BOOSTER/MASTER CYLINDER
Part #: BM1550
For 1957-1972 Ford 1/2 ton two wheel drive pickup truck. Direct bolt-on kit includes correct firewall bracketry and pedal linkage. 1-1/8" bore master cylinder for disc/drum or drum/drum applications.
http://www.mpbrakes.com/products/produc ... uct_id=169

FORD TRUCK 8" DUAL DIAPHRAGM POWER BOOSTER/MASTER CYLINDER
Part #: BM1547
For 1957-1972 Ford 1/2 ton two wheel drive pickup truck. Direct bolt-on kit includes correct firewall bracketry and pedal linkage. 1" bore master cylinder for disc/drum applications.
http://www.mpbrakes.com/products/produc ... uct_id=168


Based upon the listed applications, I'm assuming I should go with the 7" (BM1550) kit if I order from there? I'm going to be riding drum/drum for a while, but eventually would like to go to disc/drum or disc/disc if I can conjure up the fundage. However, the 8" does not say it is for drum/drum applications. These are both $299, so no price difference.

Which one is the "right" one for my 67, given my current setup and future plans? What is the main difference? An 1/8" of bore? Can someone explain why the smaller booster has a larger bore, and vice versa?

I should add... has anyone used either of these on their 67? From a seperate post by Keith, I was led to believe they were different for 67, but this makes it sound like one size fits all for '57-72??

[fordman]

i would contact the company and ask them directly what they can tell you about the push rod for the brake pedal on a 67. ask them how long it is vs the 68-72 brake pedal rod. that should give you the answer you need. booster size could have something to do with engine size . if the booster is to big it could interfear with the valve covers. and then you might not be able to mount it.

[Supermike]

Thanks, fordman. I PM'd "Calvin Gunter" because he indicated in the other thread that he had ordered from Master Power for his 67. He also indicated there was an issue with the adjustment with the kit parts, but it was resolvable. Apparently the push rods in their kit are adjustable (not sure how -- would like to see a picture).

If anyone else has any input, I'm interested. I'm just trying to learn as much as I can about this stuff.

[Calvin Gunter]

Hey Mike,I just pmed you back,the way they make it adjustable is a threaded turn buckle.The one they sent in the kit was too long which made the pedal too high so they sent me a shorter turn buckle and shorter push rod which with lots of under dash adjusting has fixed the problem.Looking back now I am thinking maybe I could have just cut some of the threads off of what they originally sent and wouldn't have had to reorder.I don't know it's been a while since the swap but well worth the effort.Good luck and like I said in your email I have the part numbers at home I can give you. Calvin

[Supermike]

Thanks for the info, Calvin... I've PM'd you back. That might make sense on just cutting back some of the threads, as long as it would not impact the strength of the rods. Talk to you later...

[fordman]

the rod that hooks to the brake pedal in 67 is shorter than the one for 68-72 finding the correct booster with the coorect rod is hard to do for 67. so most guys have swapped in a 68-72 brake pedal bracket so they can use the easier to find 68-72 brake boosters and rods. that is why it done that way. adjustable rods could maybe be modified to work. but bolt the other stuff on and go. no modifing needed.