A friend ran across Nailhead motor in a garage and would like to know the value. So far, Google and I have discovered that based upon the block casting 1364704, it appears to be a 63-66 and 425 cubic inches. The head casting number is 1196914J comes up as 59-66 364/401/425. I didn't find out what the "J" means. I have now exhausted my Nailhead knowledge. Based upon the pictures, can anyone give me a range of what this might sell for? He did not pull back the shirt covering the intake area, but based upon what I see in the picture, it looks like the intake is missing. It may be elsewhere in the garage. I assume there is a big difference if it is a single or dual quad set up. Let's assume for now that it is available and it is for a single carb. Other than the intake, distributor cap and carb, he said it looks pretty complete. I love the finned valve covers. Of course, the big unknown is if it rotates freely or maybe even runs. Unfortunately, the owner is recently deceased, so there is no one to ask. Any and all information and corrections to my brief research will be very much appreciated. This engine will be sold to benefit the family. It is in the Cleveland, Ohio area. Thank you !!
The most important stamping is a two letter code stanped in the upper block between the thermostat housing and the valley pan cover, passenger side. If I had to guess, It's an LT motor. Let us know please!
Looks like it was installed in a 65-66 Skylark GS, as it has some good parts on it specific to that application..... rear sump oil pan, and engine mount adapter plates. Figure around $100 for the adapter plates and $150 for the rear sump pan. Valve covers $300+ Basic long block probably at least $400 depending on condition. If it's from a 65 GS it would have a 'LR' code stamped on the rail just in front of the valley cover. The GS engine isn't anything special internally, just a plain 401. But those other parts I mentioned have extra value.
The 66 blocks had a cast-in 'loop' a few inches to the left of the distributor to R&R the engine..... I think I can just barely see it in one of your pics. My 401's are '705' castings.... the 704 could be the 425. 66 425's were painted red. 401's were green unless it's a Skylark GS 401, which was red. A 66 425 would be stamped MW(edit), MZ if it was a 2x4 engine. I think what you have is a 66 425, painted green, and was installed in a 65 Skylark GS.
Thank you everyone for the replies. My friend is going back for more pictures of the areas everyone noted. I asked him to go through the garage, look for more Buick parts and take pictures of everything he thinks might be a part of this motor or Buick related. I will post them after he gets them, probably next week.
My MW came from a '66 Electra and is a 704 casting. Your engine has a rear sump oil pan, I'm not an expert in this area, but my engine had a center sump pan. I doubt that your engine was in a full size car unless the Riviera is different.
After thinking about my above answer, I will stand by it, but someone other than Buick put the engine in the A-body . The 401 (they called it a 400) was the biggest Nailhead in a mid-size Buick. In fact the 401 was the only Nailhead in a mid-size Buick.
Getting back to the original question - value - unless you know it's history for a fact, it's a core. In your case it looks like a good core - the rocker shafts and things up top are clean, and it has the aluminum valve covers. I will assume that you have attempted to turn the crank at least two full revolutions. If the engine turns freely I would say $300-400 for the engine ($400 with the intake manifold if it's a Quadrajet manifold) and perhaps another $150 if the covers go with it and are in great shape. Some will disagree with me, but it's a 50-year-old engine and will need some love. Love costs money.
3 month old thread. Maybe it sold already. Valve covers alone are $300. Rear sump pan +$150. GS adapter plates +$100. Mentioned this in post #3....
The covers by themselves, probably - but as a package deal I think $550 for the engine, manifold, and covers is reasonable. If you could hear it running, see the oil pressure, etc, perhaps a bit more. I'm thinking that it's a really nice core. To rebuild a Nailhead properly costs mucho dinero. Ask me how I know...
