MM,
Remember, the squattier the car tire profile the harder it is to get a car tire bead to pop over the motorcycle rim.
Remember, you use that sidewall height / flexibility to make it work, so doing away with a lot of that means a more rigid, inflexible tire.
And I think you will find Japanese sports car tires have very firm carcasses compared to what you used last time.
Pick a tire that will go in the envelope, but don't go super super short on the profile as it will make harder job mounting and be less conforming in hard turns.
In the end, it is all a big experiment ...... I suspect any tire that will pop over the properly greased bead will actually work OK as our Savage demands very little of a tire compared to a 2 ton (500 pound per tire) 150 mph front drive car tire that goes jest a squealing and a smokin' while drifting around a tight corner.
Looking forward to seeing it on the back of your bike.