Re: Chevy 350 pings under load.
If you can get the engine to run by retarding ignition timing a little than thats what you need to do, forget the factory specs because the engine is no longer factory, the RV cam may have been installed straight up or could have been advanced or retarded a few degrees, it all depends on the timing gear set some have 3 diffrent keyways for doing this, I forget exactly what does what but I'm thinking the cam retared 3 degrees gives more low end and advanced gives more top end, we're talking valve timing here, don't get that confused with the ignition timing, your playing with ignition timing. Aftermarket cams should always be dialed in with a cam degree wheel to verify timing events and marking the balancer, sometimes you have to make your own marks.
When I said more low end and more top end it didn't sound right, what I actually meant to say it moves the powerband low in the rpm range or moves the powerband higher in the rpm range.