Quote: I have used 273 adj rockers on a hydraulic cam 340 with off the shelf standard length pushrods. There is some valve train noise,you just hear things moving,probably 15,000 miles on the build so far. it will be hard to get a quiet, factory like noise level. expect some noise.
your noise may be attributed to the known interference issues with 273 rockers
Quote: I run isky iron adjustable rockers on my small block street car. Been in service since 1988. Never an issue. Very similar to the 273 rockers.
The rockers are Similar but not the same Just trying to make a point with the above quotes. The 273 rockers will work to a point, but they will wreak havoc at higher RPM due to the KNOWN valve spring/ retainer issues as well as being weak when subjected to too much spring pressure. CHEAP is not always good. IE: 273 rockers on a 340/360. YEAH bubba does it, and gets by but can't figure out why he gets SMOKED. It's because the valve train is HOSED UP (IE: interference that limits the motors ability to RPM) and starts flutterin a bit above 4k RPM. OK, To the OP, KUDO's to you for finding the root cause, I will say before I ran 273 rockers I would drop back to NEW stamped steel ones that most likely have the clearance needed.
