How much timing on a racing gen 3

I have had my new build out to the track twice now and have made 7 passes with it to get the EFI fuel tuning close to being right, now the focus will be timing. Timing is being controlled by a MSD 6-Hemi box. Advance is controlled by RPM only in my situation. I have had it ramping up to 30 degrees total advance at 7000 rpm which has produced okay results and the plugs look fine. I talked to someone who builds racing gen 3's and he told me they usually do best at around 25 degrees on the engine dyno with the same cam as mine, so I will be retarding things 2 degrees at a time and will see how it affects ET. I don't know how much timing these motors will take, except that I've already done 30 degrees with no problems.