Hi,
I'm referring to differences between items that would differentiate items different on 70's Challengers and Dusters with small block v-8's and big block v-8's.

Is this redundant redundancy day?

Without all the redundancies, what?

The question is poorly constructed. Try different words.

K - member if a 440 or 426
Transmission depending on actual motor
Rear End based on options
Body frame structure based on options
leaf springs based on options
torsion bars based on options
brakes based on options

etc

you really need to refine your question and then we can denote specific differences

Almost everything that interfaces with the engine is different. Throttle cables, hoses, wiring harness, exhaust, transmission, etc.

If you ever swap a big block for a small block you'll find out that almost everything needs to be changed or modified in some manner.

Duster never came with a big block.

I guess it was worded a little weird. You have answered my question though. I was mainly looking for differences in components besides the engine and transmission.

Maybe try less of this....

You are on the right track...but the stuff was better than that.

Okay.....

T bar thickness
Sway bar thickness ( not allways )
Radiator core support opening


Then some other stuff like differential, but some HP SBs could get same diff than some BBs

Rest is the same.

I would go the other way of things that would be the same. Starter wires, throttle cable, gas line, trans mount, gear shifter.