I always used longer shackles on my low budget bracket cars, to make more room for taller tires. Didn't look good but worked great.
https://www.amazon.com/Superior-13-4...0029K202&psc=1
https://www.jegs.com/i/JEGS/555/60873/10002/-1
Also used slapper bars. I assume that if you adjust the slappers to where the rubber snubbers are in contact with the spring eye, that should keep the body from coming down as far. That might help avoid some of the road contact.
http://www.how-to-build-hotrods.com/traction-bars.html
Then some have just clamped a short section of a leaf spring onto the front section of the Bird spring, to stiffen that section.
Seems that I've even seen "helper springs" for leaf spring cars. I'll see if I can find any of those, still on the market.