I've run the Edelbrock true roller double roller timing chain sets on all of my engines for decades... It's a step over the stock 340 timing chain... I refreshed an engine that I put one on that had 125,000 miles on a daily driver and the chain was barely stretched... I replaced it anyway because I only paid $50 for a new one back in those days and decided since I already had the new one to just throw it on... The old one still had many more miles left to go...