I HAVE AN 85 CHEVY C-20 LWB PICKUP THAT I AM WANTING TO CONVERT TO A SWB. I DONT WANNA PURCHASE A SHORT BED, I WANNA CONVERT MY LONGBED. DOES ANYONE KNOW WHERE I SHOULD MAKE MY CUT(S). SHOULD I JUST CUT IN FRONT OF THE WHEEL OPENING OR DO I NEED TO REMOVE SOME FROM THE REAR SECTION AS WELL? AND DOES ANYONE KNOW APPROX. HOW MUCH I SHOULD TAKE OUT? THANKS A LOT