71 Duster vs. 72 up Challenger fuel tank

Hey everybody, anybody have access to both of these model year cars? I was comparing published dimensions from Tanks inc. I need a tank for my Duster, but want more capacity than a 16 gallon Duster tank. The nuts and bolts works out to the Challenger being narrower, longer and a touch deeper. My spare tire well is crap anyways and worthless, so this appears to be a win win to me. Anybody know how the vent tubes layout between the two cars? Any unforeseen issues, I haven't thought of yet? Thanks