Crius, you are correct about the M5 Stuart. It had dual Caddie flathead V8s pushing her around. I had the pleasure of hearing them with the doors open in the back at they started up and boy they sounded nice. Unfortunately once the tank is all buttoned up and running all you hear is wheel and track noise. It is really amazing just how quiet the Stuart is while it is running. I took this video of U-Go while it was at Fort Snelling running around the museum "Parade Ground": U-GO has since been moved to the east coast and relegated back into a static display. Buying the 1/6th scale M5 Stuart on eBay is what got me back into R/C tanks and lead me to volunteering at the museum. I hadn't done any modeling in over 20 years so I ended up screwing up my M5. When it fell and cracked the upper hull I ended up parting it out on eBay.

Good luck with the build. There are so many resources out the that make parts for the Stuart.