Advice on ‘74 Duster

Bubbling in the paint is almost always rust.
In some cases, there was decorative trim on the car that was removed.... then the trim mounting clips were removed and body filler was spread over the hole. Over time, that filler can swell and cause a bubble.
Some slant six cars came with the 8 1/4" axle. It is not that common but some did. ALL 8 1/4" axles were 10" drums and big bolt pattern.
ALL the automatics available were 3 speed.

The car probably has 340 decals because the 340 is a legendary engine. The 360 came along when performance was not as big of a priority so putting 360 decals on the car may not attract as many buyers.

Price? Heck...If I could get $20,000 for my 71 Duster 340 clone when I am done, I'll be all wiggly! They have risen THIS high now?

I love these cars. I've had a few. I've always bought them CHEAP and got them running myself with junkyard engines and transmissions. I had a 73 that I used in a home movie I did in the late 90s...I had more fun in that car than any other car in my life. I drove it like Bo Duke with almost no regard for scratches or dings. Learning that some are worth over $10,000 now really amazes me.

The '73-76 Duster is still a good looking car. With a little work, you can fit '73 bumpers on it. The '74-76 bumpers are heavy and not as sleek looking.