Knee Knocker A/C

Has anybody found an under dash evaporator unit that fits early As decently, and minimizes the "knee knockin'" issue? I've test fitted several different units, both aftermarket and Mopar dealer-installed ones in my '66 Dart wagon and have yet to find one that I'm reasonably happy with... they're either too wide and restrict legroom too much, and/or too deep and protrude too far out from the dash. Would prefer an air only unit, but I'm beginning to think a combination air/heat unit is the only way I'll gain the necessary legroom, after removing the factory heater box.
0% chance of replacing the firewall for a factory A/C setup- just not happening.
Any suggestions? Pictures of what has worked for you would be nice, too if possible...
Thanks in advance!