64 barracuda rear axle questions.

so I recently bought but havent taken delivery of a 64 barracuda, it has a 408 stroker but the original 7-1/4 rear end.
so here's my questions:
I know I need a new rear end that can handle the power and I have a 63 imperial in my backyard with a 8-3/4 that I could have narrowed but im wondering if its worth the time or if I should just save up for a dana 60 (or strange 60)?
I've read that installing a dana 60 will require modification to the gas tank which makes me somewhat wary, could anyone point me toward a picture or description of the modification?

The car won't see the track but I do want it to be reliable enough that I can drive it without worrying about breaking parts and getting stranded.

Coincidentally the imperial is free if someone in the sacramento ca area wants it with the rear end.