That was the point of my previous post #8. The 570 cams have a smaller base circle than stock. IIRC, unless the heads have been decked and/or a thinner head gasket used, the OEM push rods will be about .040" short. So, at a minimum, valve train should be noisy but whether or not the too short pushrods are contributing to the rough running and backfiring; not sure but being .040" too short could be the cause of all your problems. Cut out the OEM push rods, install a set off adjustables, adjust properly and try again.

 

Thanks for the help. Will try that. Will let you know. Any opinion on the various adjustable push rod sets?

 

I have no problem with the SE Quick Install Tapered set; PN18404-08 which includes pushrods, O-rings, tubes and clips. There are some that don't like them because there were some problems with the first sets. I experienced the problem on a set but the problem with the adjustor nuts has been addressed and I am currently running a set on a healthy all bore 107" with no issues.

S&S are also good; you can't go wrong with either IMHO.

 

Quick update on the project. The engine would run, then after a bit it started to leak oil. It looked as if it was coming from both heads. So I pulled the heads, replaced all the gaskets, this time using he S&S head gasket. Purchased and installed the SE tapered quick install's.Re-assembled using the high compression SE plugs. After assembly she started right up. Still had a small oil leak from the rear top pushrod cover, which stopped after pushing it on better. Bike runs rough - like needs a tune. Otherwise seems to be good. Again, thanks for all of the advise.