Ok, I sold my two items on ebay, gonna take the plunge and order the Tsunami with correct 710 prime mover sounds, along with one of the nice oval speakers w/enclosure from Tony's train exchange tomorrow. It was a toss up to either put sound in, or put an overland chassis under the shell. I think the sound is going to win out. The stock blue box chassis runs smooth and quiet, one of the quietest I have heard in awhile. I have it appart right now and if I run just the motor and flywheels in my hand, there are no vibrations from out of balance flywheels or motor armature. I had to body mount the couplers as both ends of the 4610 have big snow plows on them. I got the long hood ditch lights mounted, just need to get more bulbs for them and the main headlights. Tomorrow I hope to get the numberboards done and the rest of the lights installed. Then I can glosscoat the whole unit to look paint shop fresh. I cant wait to hear that 710 fire up with its signature "ying, ying, ying, ying" idle chant. This will be my very first DCC/Sound install, should be intersting. The plan is to put the decoder ontop of the motor and the speaker below the rad fans facing downward with enough room behind it to access the rear headlight. I hope to mount everything up in the shell with just the feeder wires to the chassis. I think that makes the shell more easily removed for chassis lubrication. I havent seen a good way to mount everything to the chassis in a blue box engine. With 8 wires from each end's lighting, keeping the whole setup at the top of the shell is best, I think! Cheers Mike