I should buy the correct nuts like these, it's too bad they're not locknuts. Which is the reason mine have been replaced with nuts and washers.
64-74 Mopar A B E Body Road Runner Cuda Dart 1-1/4 Inch Washer Seat Nuts (8) | eBay
Old hot rod buddy of mine told me he had to reinforce the firewall because it flexed so much with a heavier clutch in his 65. And he was a little guy, like 5'4"
If you decide to pull those back seat window regulators make sure to put witness marks around the bolts before removal. Getting those adjusted properly must have been a black art
I'm guessing into the rocker, but from what I can see there's only one 1/4" drain hole beneath the rear passenger window and it was hopelessly clogged. I might drill an extra hole and do WD40 as suggested
Oh that makes sense. Is there a telltale location in the front that would also have witness marks? I know the hood and driver's fender are off a different vehicle.