I'm looking to get my 1954 Chevy 6500 2 ton Dump truck back on the road and would like to upgrade the old Lowe gear SM420 4 speed to posable with a NV4500 5 speed with OD only im having trouble in finding an adapter to allow me to keep the original 235ci L6 cylinder. I'm sure there is a adapter for me to use a T5 but I need something more heavy duty since it's going in a 2 ton dump truck. Any suggestions would be appreciated.