Allison Man, I spoke with you about my problems with my Bounder MH with the 5.9 Cummins and the 545 trans back in March. I have since removed the exhaust brake so I don't destroy another trans but have not detuned the motor (now at about 300HP). Your suggestion was that I either change the trans or get another MH. After much searching I have decided that changing the trans may be the option I'm after. You said that I would need to change the bell housing and the 643 is longer than the 545. Can you send me specs on the 643 or direct me to where I can find them so I can further determine if the swap is feasable. I will be doing the work myself in my shop so the cost may not be overwhelming. Thanks again for your call last time and I thought that I would call you again if that would be OK? I appreciate your help.