2 part question. pro parts headers and A/C heater box.

I am building a low deck for my 70 swinger. The car has A/C. I removed everything but the heater box. Will the engine fit with the A/C blower motor, or do I have to get a non A/C box?
I will be running pro parts semi fenderwell headers. I have heard they aren't that great on a low deck?? Any info/tips are well apricated! Thanks!

I have used ProParts on low decks and RBs. The only difference I saw was the inner fender cut outs were made about 3/4" lower. I actually shimmed the motor up closer to RB height. The blower motor interfered with the passenger valve cover. It was either grind the fins on the valve cover or remove the blower motor. How far out does the AC box extend? I think the headers are well below that point. I also read an article that tells you how to move the blower motor more towards the passenger compartment. Maybe thats a way to go. Hope this helps you.

Here is the blower motor mod Heater Fan Motor Mod for Added Engine Bay Clearance
and another How To for Heaterbox Motor Modification