In your case you already have all the sb setup. For the money you would need to throw at it to convert over to BB. Youd be money ahead just to stroke it. IMO

You already run pretty fast 11.5,s For a little more dough 10.5,s are just around the corner.

Id research the most cost effective sb stroker.

How many are there now. 370/408/412/418/440 and is there a 500 now, after market block I take it.