I have a 48 chev panel one ton with a 235 and a 4:56 rear end and I from all my reading it looks like I can only swap out to a 4:11 which will not give me what I need for the highway. It looks like I should go to a different transmission. It looks like I should go with a OD trans. Are there any OD trans that will bolt up to what I have. Someone said that A833 and NV4500 are good alternatives but not sure what trans these are. I am new at this but learning with the help of this site. The numbers for my rear end 3rd member is 3699535 and the trans 591665 if this helps. Thank to all