Timeing correlation on a 350 vortec P1345 code

Question

Ok i have a p1345 code on my scan tool I have replaced the distributor and the cam sensor in the distributor because my truck is 20° Advance on timing with the RPMs at 1000 so I thought it jumped a tooth so I pulled out the distributor and notice to cure on the distributor was a warrant out so I replace the distributor put it back together and still does the same thing