Now remember, you ordered the Hydratech model #3507 with the late / short MC pushrod design:
Soooo, be sure to insert the spacer bullet / plug / slug into the deep hole on your master cylinder to convert it for use with the late model GM short pushrod design on your brake unit, otherwise you will have no brakes (!)
Most all aftermarket MC designs are of this "convertible" design - the MC is provided with the GM early spec deep pushrod hole, though the MC is also typically supplied with the "conversion bullet / slug / plug" that converts it for use with the GM late / short MC pushrod interface.
Note that we do not supply this item - it is supplied with the aftermarket brake master cylinder. You are using a 1 1/8" CPP MC, right? These are typically the "convertible" spacer bullet type design. I suggest you bench bleed the MC first with the deep hole, which helps to keep your screwdriver from accidentally popping out of place and gouging the MC piston bore. Once the MC is fully bench bled, then you put a dab of grease on the front of the bullet and push it into the deep MC pushrod hole (to help make sure it doesn't accidentally fall out at any point while your handling it during installation onto the face of the brake assist unit). SSBC has an instruction sheet that discusses and shows the installation of the spacer bullet in their MC's for general reference:
https://static.summitracing.com/glob...-1-2-3-4-5.pdf
So now we'll all sit back and watch how this system installation goes for you - definitely keep us posted. If all goes according to the plan, you will have a big fat smile on your face here shortly!