The majority of these cars differ dimensionally for one reason or another so take fitment feedback accordingly. My inner rear wheel clearance is tight and I can get a little sidewall contact in faster undulating high speed corners. Leaf springs without allow some lateral movement. I've clearanced the contact points including new tail pipes and wouldn't say it's a safety issue, but on certain tracks it could be. Ideally mini tubs are the proper way to fit this size tire.
For the wife's cruiser you should be fine, but you'll need to watch it. Make sure the rear end is sitting square and centered in the spring and then test drive with a full tank and maybe a little weight in the trunk and pull the wheels and check for contact points.
Rear drum brakes are fine for street use they just don't dissipate heat well or look cool. If I had to do it all over I'd trade rear disc's for the C-clip set up. I've seen enough high horsepower cars utilizing none C-clip axles on track with no issues to support my opinion. I wouldn't cheap on the axles though.