I have a 36 Master Sedan with Progressive's front kit for C4 Corvettes. The frame on a 36 Master is the same channel style as AD pickups though not so large nor as wide. The install was a one day deal with help from a friend. I was impressed with the quality of the front crossmember and the rest of the kit. They also furnished an 83-88? Thunderbird power rack and pinion that had been rebuilt (same 3 turn lock to lock as Corvette) and a top plate for the upper A-arms as well as the through bolts for the lower A-arms and fasteners. I'm still building so can't vouch for the drive but the install went well and instructions are pretty straight forward. I called Progressive for one question and they were most helpful.

I'm wondering if you thought about using the Corvette crossmember and steering instead of a kit. I think you are wide enough between the frame rails. I looked at doing that but didn't feel comfortable whacking away as much crossmember or frame as fitting the corvette x-member would have required on my narrower 36 sedan even though I have seen another 36 that did use the corvette crossmember. I studied how it could be done and by whacking away the engine mounts on the corvette crossmember you gain the room and a much cleaner looking install. Likely you would want your engine mounts further back anyhow. The advantage of using that is that you have the factory geometry. The only concerns I can see are that 1)it may be too wide though the use of backspaced wheels can overcome a lot of that and 2) its going to set you down in the weeds unless you do some innovative mounting of the corvette ifs on the chevy frame. Might be you could set the frame rails higher on the corvette crossmember but that stil leaves the crossmember barely able to clear a brick on the road. Even my progressive setup on my 36 puts the crossmember where the brick has to be laying in its lowest position to clear.

FWIW I used motor mounts from Chassis Engineering that look like flathead ford mounts. They work great and look pretty cool.

A tip: think about your steering shaft mounting when you think about motor mounts and make a template out of a broom stick or pieces taped together with duct tape to figure out ahead of time how you are going to do that because they will be fighting eachother for space most likely
Jerry