I ran 273 rockers on a low 12 sec 340 for many years. Repeated trips to 7000 rpm's with a solid cam with no failures. Just had to trash the original adjusters for a good set with lock nuts and grind a slight relief for retainer clearance. I still have this set of rockers and am going to use them on my 69 340s 4-speed car. Yes there are better rockers to be had but the 273's worked well and are very durable. But then again I'm on the frugal side, if I have it I will use it instead of buying new. I use ductil iron rockers on the big block in my race car also.
