I saw a 70 e body with a later pad. Car had ac and now doesn’t have the vents either. Any problem swapping back to a 70 pad if lower frame was changed to a later year as well? Any difference in an AC lower frame and a non AC? Can you swap a pad without taking dash completely out? Seems the b body requires the windshield to come out to get dash out. What about these cars?

Dunno on the dash pad question, but 71 and lates B bodies don't require remove windshield to pull out the dash frame and you can make to remove the dash pad from the frame with frame in place... Althought tricky. I think E bodies are similar.

Adding info

https://www.forebodiesonly.com/forum/threads/72-challenger-padded-dash.3761/

Late 80's I was able to swap out pad on my '70 Challenger while frame was still in car. Mine was non AC so there was a little more room to work. AC box and all that goes along with it may really complicate things . Took out front seats and a 1/4" wobble extension will help. Put your chiropractor on speed dial.
Also on my '71 charger the dash can be R&R with windshield in place. Just don't drop any screws down defrost vent. Don't have any experience with '70 and down B's.

E body dash frames are all the same 70-74 regardless of AC or not, rallye instrument or standard cluster, you can change out the pad in the car, tedious job, it sounds like more work but it's actually easier to pull the whole dash and bench it, to pull the whole dash, remove the A pillar trim, 2 screws in each windshield vent, 1 bolt inside each kick panel, drop the column, undo the speedo head/cable, wire harness/bulkhead, vent/heat cables, then pull, no need to remove windshield that's a 2nd gen B body deal


MikeG

Taking it out would have to be better deal, thanks. Not sure what heater box it has. The evap coil hole is plugged as seen underhood. Good to know I could fix the head shaking decision to put the later pad. Thanks.