M123 10 ton exhaust options

I never was close enough to pay attention to the exhaust setup on our ten tons, but the ones I was around in Nam either had stacks or went out the sides in front of the rear tires. Stateside they were like that with plates in front of the pipe to deflect the exhaust. Anyone have any more info on this as I want to do at least a Nam one and possibly a stateside one too. Thanks, Wayne