If you want to stick with AMC parts then get the 360. There is no substitute for cubic inches and it's the same basic block! Your T-176 with aluminum case is of marginal strength behind a strong running 304 or 360 so take it easy with either engine. Recommend a trans rebuild while you have it apart. I get sick of paying twice as much for performance parts and pulled my 304/T-15 drivetrain. Replaced it with a Chevy 350/NP435 combo. Easy swap, used readily available aftermarket and production parts to complete it.
Doors? I don't run no stinking doors.
'45 Ford GPW; '73 CJ5, 350/NP435/D20 w/Terlow gears, locked D30/D44; '13 CJ8, 304/T150/D20/D30/AMC20 w/locker and limited slip (T18 and Teralow gears in future); '88 Dodge RC, 360/NP435/NP205/D60s