Setting cam timing on 500sec
 

I am having trouble getting the timing marks to line correctly on my 500 sec. I can get the drivers side cam to line up perfectly but the passenger side will not line up. If I move the gear one tooth forward it is slightly ahead of the mark and if I move it back one notch it is behind the mark. I have a new chain and new gears and new guide rails and new chain tensioner. Any suggestions?

yes set it up behind the mark not ahead.this is normal.

It may be off by up to 3 degrees even with a new chain.
Any more than a marked 3 and you will want to verify the cam notch is accurate. There may be an offset key in there put in by a previous owner/mechanic which makes it advanced with the new chain (or retarded if the key was put in backwards).