Dynamometer Results & Comparisons - should converter be locked on dyno

should converter be locked on dyno when tuning it? and what should timing be on a 402 withstage 2.5 ls6 heads and 252 256 cam 629 lift 112lobe sep ps headers tsp tds fast 90/90 and all the little stuff. timing was 26/27 and power was450 hp on mustang dyno and 530tq a4 with 2800vig converter top end everthing on top end fell off quick this is my bro's car just trying to help him out.

Lock it to get more accurate #'s. My locked vs unlocked #'s are a difference of 26rwhp and 34 lbs tq.

That would be on the inertia drum dyno..


What about on the new "load bearing" style dynos???
Just slap it on & tune it since you are tuning it the way it is driven on the street essentially??