The only other spring I replace is the latch spring on high pressure chamberings(FAQs), not really an issue on the 30-30 unless you were hot rodding it which I wouldn't advise on a cast iron framed Topper with the brazed/soldered underlug. I always cut a coil off the trigger spring to help reduce trigger pull weight a little, but best advice is do the hone first (if needed) then shorten the spring if you want a lighter pull, otherwise leave it as is. I've done a trigger job on an older M158, the sear notch was very deep and really not easy to lighten very much without removing a lot of material which can be scary cuz once the surface hardening is removed, they wear quickly and can become unsafe too soon, got it from about 10-12lbs down to ~4lbs just by polishing the mating surfaces and called it good.
Tim