Screw spacing is the same as a large ring - easiest way is to glass into a large ring stock.

http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/7669896/Re_1640_in_a_98_stock

You can pretty much use any 98 stock but the factory bottom metal needs fitting not quite the same as a 98 bottom metal.

Last edited by Loosecat; 02/07/16.