Is a cobra booster needed?

Keep in mind, with rear drums the considerations for MC and booster are different than if you were running rear disks. They hydraulic needs of wheel cylinders vs 38mm calipers is different.

There actually isn’t any MC to swap to as the smallest 4wheel disk MC (94 cobra) is still too large for wheel cylinders and will give you a hard pedal.

I often tell folks doing front sn95 brake upgrades to just try it first on the stock MC/booster and see how it feels. Usually it’s pretty darn good.


Rear disks, my answer changes
 
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There are threads in the tech/how to thread at the top of the 5.0 tech forum, also look in the resources area for more info on brake master cylinder fitting sizes for 85-93 brake systems, basically you need to update, @Noobz347 had a thread posting cobra booster (for 4 wheel disc) part numbers and if I remember, where to buy them. LMR is not the only place to buy them and likely for less money. I think you can use a common 87 up booster for rear drum/front disc brakes with the proper master cylinder.
I think you could use the lines from a 87-93 mustang along with distribution block from the same 87-93 models with minimal adapters if any.
Can anybody confirm this?
I might have pinned it but the thread you're talking about was probably started by @Mustang5L5 ?
 
I might have pinned it but the thread you're talking about was probably started by @Mustang5L5 ?
It was about cobra boosters being out of stock and you gave part numbers, I think it was because a member was confused about which one was actually a cobra booster or something or stuff. It used to hang in the tech stickies but I don't recognize it, doesn't matter, he has rear drums on a 9" .
 
 
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I did the pbr fronts with the stock sn95 rear disc on a fox, just ended up using a sn95 booster setup. Slotted the holes a little and massaged the shock tower a touch and it went right in.

Gutted the stock proportioning valve, tapped it for a plug, and used an adjustable one - but I don’t think that’s needed with drums.

I’m with the others that say just try it with a factory booster first though.
 
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