I have a 98 ram 3500 2wd with a 12 valve and an auto trans. my temp gauge quit working and i ended up seizing up my engine. I am about to tear it apart and fix it but i want to do this right because i want to use this for making long hauls with a 3 car trailer and i need to find a balance of power and fuel economy. I am looking for advice about what do use to rebuild my engine and if i should rebuild my auto trans or if i should put a 5 speed in that I have from an 87 donor truck. Any advice would be welcome.