The cost to deck the bottom of the block is really negligible usually around $100.00, our girdle interfaces with the caps to help hold them down, so you are not relying on just the main studs to hold them in place.

also our oil pan studs have counter bored holes in the girdle so you can bolt the girdle down tight to the block. then if you want use a gasket between the girdle and oil pan. some guys will cut a rubber gasket and install that so they drop the pan and inspect it as needed. this way you don't have to bother the main caps or the girdle.

plus we don't use longer studs to secure girdle to the caps. we use a secondary set of 3/8 bolts to hold the caps to the girdle. this eliminates double stretching the main stud. we also secure the #1 and #5 cap to the girdle with an inboard set of 3/8 studs.