GMT 400 Hydroboost swap

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Whipped96

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I don’t have an original hydroboost, I’m swapping from vacuum brakes.
 

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GM Hydroboost 178-0982
Was $131 when I bought it a week ago, price went down since to $113 at the time of this posting.
It fits an ACDelco Professional 18M2404 master cylinder that I have.
Also, the booster comes with the spring, spring retainer, and rod in it, albeit a plastic rod. (Edit - It's a metal rod, it's just painted black, I just took it out setting the rod to master cylinder clearance)
I have a cardboard template of the firewall gasket I made when I replaced the gasket on my original vacuum booster. The backing plate bolts fit that pretty well, I won't know for sure until i get a chance to install it.
The rod end for the brake pedal measures 0.600" and is stamped 778501.
Anyways, here's the link

www.amazon.com/dp/B08MR128KY/ref=as_sl_pc_tf_til?tag=&linkCode=w00&linkId=&creativeASIN=B08MR128KY

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RichLo

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What years does that fit? Thats half the price of the cheapest one on RockAuto for my 97 k3500.
 

Erik the Awful

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You need to remove the "http://" from the front of your link or the forum eats it.
 

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The price is down to $92.07 as of 4-10-2022

Update - got the hydroboost mounted and the mounting holes are the same as my original vacuum booster. The truck is an '89 C2500 8 Lug that originally had a vacuum booster but the firewall hole was formed to accept both so it just bolted right in. Not sure if all the trucks were built with the firewall that way.

FYI - If I were to relocate the brake pedal pin slightly higher, the brake pedal push rod that came with it is about 9/16" too short. I'm probably just gonna cut it and thread it 3/8-24 to accept universal push rod ends.

Something like this one I found on Summit, Won't need the rod but will use the Heim joint and the dust boot
www.summitracing.com/parts/clp-cpmpr-u1
 
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