What does look like under the valve cover? I would bet a critter found its way up the exhaust manifold. Mice seem to pick the most expensive places to build a house. Looks to be a recent deposit in the woods?
I question the "New Old Stock". The black/silver tag on the left of the engine near the bellhousing looks like a rebuild tag to give bearing sizes. (Possibly fresh from a rebuild but probably not NOS. Remember the military's passion for "everything in its place". The crate might have been re-used for shipping/handling convenience.)
Based on the condition of the cylinder head under the valve cover, it does not look like it has seen much use.
Would bet that engine is from/for a DUKW (aka "Duck") 2-1/2 ton amphibious truck.
Many features are consistent with that application:
Four blade fan with reverse pitch (DUKW pushes air through the radiator as opposed to pulling it).
Shallow oil pan. Engines with later features such as on this engine (6 valve fuel pump. cast iron carb., distributor shield) would have the deeper two piece oil pan if used in a conventional truck.
Also not sure, but I believe that the adapter bracket on the front damper is for the compressor in the tire inflation system.
On the right side of the engine, just to the rear of the distributor, there is a flat machined pad with a number stamped into it.
The first three digits represent the engine displacement. It may be a little difficult see with the distributor shield in place.
Can you post a pic of the metal plate on the left side of the engine? If it is an arsenal rebuild, it may say where and when it was rebuilt.
It is almost definitely the military version. Features like the distributor shield, the wide pulleys, and the cast iron Zenith carburetor are unique to the military version of this engine.
Will it fit? Of course it will. Depends on your skill level and how fat your wallet is. Some modification required. It will be awesome when done.ðŸ›
Martin '62 Chevy C-10 Stepside Shortbed (Restomod in progress) '47 Chevy 3100 5 Window (long term project) ‘65 Chevy Biscayne (Emily) ‘39 Dodge Business Coupe (Clarence) “I fought the law and the law won" now I are a retired one! Support those brave men/women who stand the "Thin Blue Line"! Hug a cop! USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
Yes but its not a drop in and play. the GMC' 6s are 1.5" longer than the Chevy 216, 235 and 261.
Modifications will need to be made to the front or forward crossmember to extend it 1.5" to accept it. The radiator will need to be moved forward to compensate for the fit of the water pump and fan.
If this is a military engine - more than likely the front timing plate with the front mount bolts will need to be installed from your existing motor. There is a list of items to be completed to convert from military to civilian application found here on the site, and Inliners International website. Your flywheel from your existing motor may or may not fit depending on the flywheel bolt pattern. I have done this twice now. .
This will open up a broader discussion as to what you intend? Do you want more power? is your existing motor needing an upgrade and rebuild?
Finding a Chevy 261 will get you very close to the GMC 270 and will not require the modifications, effort, cost and time to convert your GMC. But, its a fun project to do -if you are inclined. Basic tools and a willingness to roll up your sleeves is all that is really required. If I can do it - you can.
Of course you can put it on a pallet and ship it to me? That is always a viable option.
My Chevy has its original 216 with very low mileage after a rebuild. It runs great and I have no plans to change it out anytime soon. This engine was available so I picked it up. I understand that this is a better engine than the one I am running, but the one in the truck runs fine.
There is nothing wrong with a nice running 216. The original engine on the truck is always a consideration. But if your truck is on light duty, and for hobby use and driving, the 216 has a long track of working well. Of course with time, are the improvements to design - and the 216 may not have the improvements for oil and lubrication as the 235 and 261's but hey, so what? Finely tuned and operating correctly - it should give you plenty of enjoyment and dependability. After-all you cant take it with you - but you can always send a 270 on a pallet. LOL!
Should you decide to move it on to someone else, post an ad in the Swap Meet Forum. It won’t last long.
Martin '62 Chevy C-10 Stepside Shortbed (Restomod in progress) '47 Chevy 3100 5 Window (long term project) ‘65 Chevy Biscayne (Emily) ‘39 Dodge Business Coupe (Clarence) “I fought the law and the law won" now I are a retired one! Support those brave men/women who stand the "Thin Blue Line"! Hug a cop! USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
Nice find. Actually awesome. Sounds like it didn't cost you a dime but your time. Better yet to boot. Stash it away and see what happens in the future. You might need it, might not. Get tired of looking at it, sell it, make a few bucks, and give someone else the opportunity to use it. I wouldn't throw out my freshly built 216 by any means, well unless it bit the dust and i had that motor sitting there. I ran my leaky, smoky, 216 for years. Only changed it because the clutch failed, 2 gear was noisy and it had to come apart anyhow. I had 261 waiting in the corner along with another trans and rearend. And glad i did. You wont have to feed that 270, so it wont cost anything, but space, to sit there either.
If you do decide to sell, another consideration would be listing it on some of the military vehicle forums. That engine has a lot of desirable content for someone looking to install it in a either a DUKW or a CCKW.
You now have 5 so you are no longer required to have your posts approved.
Martin '62 Chevy C-10 Stepside Shortbed (Restomod in progress) '47 Chevy 3100 5 Window (long term project) ‘65 Chevy Biscayne (Emily) ‘39 Dodge Business Coupe (Clarence) “I fought the law and the law won" now I are a retired one! Support those brave men/women who stand the "Thin Blue Line"! Hug a cop! USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
Thanks to all of you for the advice and expertise. Haven't made up my mind what to do with the engine, but considering my 216 (original to the truck) runs fine, it is unlikely I will undergo the necessary steps to modify my truck/this engine to fit.
Crowbar Bob- you mentioned military vehicle forums. Can you direct me to them?
I love my '52. I bought it from my grandpa, my other grandpa rebuilt my 216 (both are now gone), but this hobby is way down on my list of hobbies!
Also- I too am listed as a "new guy" which I find hilarious, as I am not a guy.
C'mon guys, do I have to correct my 30+ years old daughter's and 5 years old granddaughter's use of gender-non-specific "guys" (so that my one year old grandson does not use "guys" in a sexist manner)?
Crowbar Bob- you mentioned military vehicle forums. Can you direct me to them?
These two are dedicated to the DUKW (amphibian) and CCKW (conventional 2-1/2 ton truck), which both used the 270 engine. They contain a lot of information concerning these vehicles and their related components.