Lunati 704
It could be carberation. Thought about that also.
It kindof depends on if there have been changes to; your operating elevation, or the ambient temperature. Lemmee see if I can remember this right; A change of 2000ft or 30*F, is one jet size.
I have a Hughes cam advertised at 276/286@ .008 tappet rise =230/237 @.050 on a 110, with a lil more lift, in a 367+.040=367 so similar to your 340=.030=345. At 930 ft elevation, I run 78/86 Holley jets in an ancient 750DP on an Airgap with TTIs and a dual 3" system.
As to the noise, don't forget that the pushrods can occasionally rub on the tunnels. AND, with stock 318/360 rockers it is possible for the rockers to rub on the retainers; not so much with the clearanced 340 rockers...... but with the lift over .500 you gotta check.
