The Stovebolt Site Forums The Shop Area Engine Shop GMC 270 Engine

During WWII, GMC made nearly 600,000 trucks with the 270 engine. Most went overseas, and many of those continued to serve various NATO countries thru the Cold War era. As the US transitioned to more modern vehicle designs in the early 1950s, nearly all of the GMC spare parts were sent to European allies in support of these vehicles.

Consequently, there are literally tons of parts available on that side of the pond. Several years ago, one of the vendors I talked to purchased the stock of a competitor that was retiring. He told me that he moved over 20 tons of parts to complete that purchase. I read someplace else where a guy purchased several crates containing 80 brand new crankshafts. Many places have NOS pistons, rings, connecting rods, bearings, rocker shafts, valves, valve covers, etc. etc. A lot of this stuff is still sealed and packed in cosmoline, with dates from the early 1950s.

If your goal is just to rebuild, then I would not bore any larger than the recommended 0.060". If you are looking for stock pistons, they show up on the various auction sites quite frequently, as do rings. Just do search on "CCKW" and "270", or "DUKW" and "270". If you find a vendor with a variation of the part you need (i.e. 0.040" over pistons), shoot them a message as they may have what you are looking for. It is worth noting, that the stock WWII era 270s had very low compression ratios - like in the neighborhood of 6.75:1. Not sure if that would be a factor for your build or not.

If your goal is more performance oriented, then as Jerry suggests, I would start looking for a 302. All of the postwar GMC 2 - 1/2 ton trucks had them (M-211 & M-135, for example). A lot of them got left in Europe as well. This series of trucks tends to be shunned by military vehicle enthusiasts, so they can usually be picked up for a reasonable price.

Best Regards