The Stovebolt Site Forums The Parking Lot Big Bolts 1937 GMC COE F-33HD...3B?....Spanky?

My Motor's also only lists up to 400 cu in engines. However, GMC built a 707 cu inch engine from the mid 30's until the late 40's. It was mostly used in fire apparatus. The only one I have ever seen had an accessory drive with a direct coupled air compressor and had two spark plugs per cylinder.