273 Commando Rebuild Or Not?

The possible downside to running heavier valve springs is the extra wear on the cam and lifters. If it's just going to be a cruiser and not going to be revved way up, why do it? No upside IMO. The existing cam and lifters are used to those springs.
Not much different at .425 lift, but less false motion. I pretty much run them on everything. But I don't run anything but a 4 barrel carb and rev to 6,000 rpm. When you use good parts, longevity is a non issue in my experience. Most of my engines last forever with oil and filter changes at 3,000 miles and 20w50 Valvoline VR1. Actually I have never had one fail yet, except the cam and lifters in the stock 318, and that was a small tick at idle. To be fair it was a factory engine with 30,000 miles and it sat for years before I bought it. Fixed it with a small Mopar Performance cam and lifters, still running like new or better 20 years later...