There is actually a Ford GAA engine up for sale on Ebay!
http://www.ebay.com/itm/Ford-GAA-GAF-V8-Sherman-Tank-Engine-Blocks-and-Parts-/261539470162?pt=Other_Vehicle_Parts&hash=item3ce4f79b52&vxp=mtr
I've had my hands on those engines...really a sad story.
An old man supposedly had a huge barn full of good stuff that burned down in one of the big San Diego fires. Well lets just say he stretched the truth a little on his insurance claim, but he got a big chunk of money. He went and bought all kinds of stuff, but with nowhere to put it he loaded up a couple of hangers at the local airport. He tinkered for a couple more years, and then passed away.
One of his nephews was left with all of the stuff, and I helped him identify and sell some of it. There was hot rod parts, air plane parts, motorcycle parts, machine parts.... you name it his uncle had collected it. None of it was real nice, but he had replaced some of his collection. There was a Boss 302 block and heads, some 428 parts, and a jung 427 MR mixed in with all of it.
The sad thing about the tank engines was there was 3 times what is listed in the ebay ad, all in spare parts crates. The nephew got behind on the hanger rent and just started hauling stuff off in trailers. Before he could get it all out the landlords locked up the building and took the engines listed on ebay as collateral against the back rent. The nephew decided he would never get them back, so he scrapped all of the missing and spare parts that went with those engines.
