im building a 71 gmc truck for my brother it has a 1998 vortec 454 and 4l80e and a np205 and kingpin dana 60 and 14 boltff out back we are installing a hydroboost off the donor truck onto the 71 and i need to know how much the pedal drops when you start the truck if any and how much rod travel i need from the pedal any info would be great

from what i rember they dont drop at start up. i will check one tomorrow and let you know i let you know about the rod travel also

look forward from hearing from you thanks for your time
do you have a 1998 chevy 3500 thats was the donor truck we used
we also cut about a foot off the dash and used it and the colunm and put it in the 71