Sounds like you didnt have the miss before you pulled the heads?
If that is the case did you route the plug wires per the TSB in the
FAQ's section? https://dodgeforum.com/forum/2nd-gen...bulletins.html

Dave

 

A buddy and I did a leakdown test on cyl. 6 and 8 and didn't hear air going anywhere. The cyl.s didn't lose much air at all.

Xjarhead....your absolutely correct. I didn't have a miss before I pulled the heads, and I've rerouted the sparkplug wires according to the TSB as well as put extra wire loom over each wire. I can't even get the truck to idle now, but that may be because I've reset the fuel sync and haven't driven it enough. No codes are present on the ecm now. I've added a ground onto the motor in the chance maybe it didn't have a good ground connection. Still no luck.

 

Ok, possibly a silly suggestion, but...... do you have the connectors for the fuel injectors on 6 and 8 swapped by any chance?