Hy Casey_58, The kits for the front wheel cylinders are Raybestos part number WK129, $2.78 at RockAuto. I believe that the front wheel cylinders are no longer available as assemblies. There are wheel cylinders that are the same bore and mounting but that have the hose connection at an angle rather than straight out, others on this forum have installed them as replacements with no issues. The part numbers for these wheel cylinders are Raybestos WC19090 and WC19091. The master cylinder kit for your truck is MK33 $14.34 at RockAuto. Your rear wheel cylinder kits are Raybestos part number WK 147 for ring style cups or WK195 for solid cups, WK147 is $10.09 and WK195 is $4.26. If your rear wheel cylinders have the crossover line on the inside of the brake backing plate then you have Bendix rear brakes, the nuts on the crossover line have a different pitch to those on a standard brake line, these are made of unobtainium so do not loose those lines or throw them away As to your Hydrovac contact Geoff at Alretta truck parts he will either have an exchange unit or he can have your core rebuilt, hope that helps.