hydroboost questions. difference between 88 and 95

[weazel]

ok, been doing some research, and cant find any solid info on my question.

question is, im doing the conversion in my 88 half ton, converting to a hydroboost setup for the brakes. tried installing the hydroboost from an 04, but pushrod is wayyy too short.

at the kind of local junk yard, theyve got a hydroboost out of a 95 model truck that had a 6.5 in it. what is the difference between a hydroboost setup from an 88 to a 95? are the pushrods different sizes between the 88 and 95?

 

[weazel]

well, since i had no luck finding this info out, i went ahead and purchaed a brand new unit for an 88... or so i thought...

got the new part, installed it on the truck. went to install the master cylinder, and hmmm, the dang thing wont fit in the hydroboost! ended up breaking the master cylinder, so off to the auto parts store again...

before i went, i had a strange feeling something wasnt right to begin with. so i grabbed my calipers, and measured the bore on the inside of the hydroboost. got to the auto parts store, and asked for a MC for an 88 with a 6.2. they told me the PN's were the same for the diesel versus the gasser. had them pull one off the shelf, and measured it. sure enough, way too big, just like my original!

got to thinking, and said, hey grab a MC for a 95. they pulled it out of the box, and sure as shit, the thing will fit the hydroboost i got from the other store!

so to answer my own question, and maybe someone elses in the future, the differences are, the 88 bore is bigger than say a 95, and the eye of the pushrod that hooks to the brake pedal is smaller on the 88...