You can use any year S-10 or S-15 chassis from 1983 to 2003. The ideal chassis for the ’41 Willys Coupe is the 108” chassis which is the standard cab short bed.  To use the longer chassis S-10 (117” Or 123”) for the coupe you have to shorten the chassis in the middle to get to 108”.  Then do either a four link or a ladder bar rear suspension to get to the 102” wheelbase required for the coupe.  Otherwise the rear kick up of the rails will be in the coupe floor. You can also back half the chassis for a pro street but will still have to start with the 108” wheelbase.  For the ’41 Extended Pick Up you can use any wheelbase but you will have to adjust the length of the bed to accommodate the longer truck. The S-10 radiator is about 40” wide and will not work in this application.  We have used a custom radiator built by Superior Radiator due to the narrowness of the space between the fenders in the front.  Other modifications will include a new set of motor mounts that will move the engine about 9” back to where the damper pulley is over the cross member.  This is true for the V-6 and V-8 applications.  Instructions will be supplied with the purchase of a ScottRods Willys Body Package.  Please specify when ordering if your Willys body will be mounted on an S-10 Chassis.