The Stovebolt Site Forums The Shop Area General Truck Talk 1956 1957 with a nail head

Does anyone out ther have a nailhead powered truck. I have head of them but have never seen one. I have a 1959 gmc and would like to put a 401 nailhead I have in to it. I just want to see how the factory did it.

That is a new one on me. I have never heard of a nailhead engine. What is it?

the factory didn't do it - GMC didn't use Buick's - not sure how they mounted the Pontiac 336 that was the V8 for 59

Bill

I agree with Red. Alot of them were used for engine swaps in the 50s-60s. A nailhead engine is a Buick v-8 up to 67. So named because they had a small exhaust valve Kind of looked like a nail.

I read where the valve stems come straighr out of the head as apposed to on an angle, and thus the term nail head.

According to a guy who worked in the factory (Janesville probably), GMC used Buick and Olds V8s in some big trucks.

They apparently were unreliable in big trucks.

Red;

The Pontiac engines in GMC's used a single front mount,similar to the early 60's Chevy V-8's in the one ton and bigger trucks,only it didn't fasten to the block,but rather it attached to two ears that were located on each side at the bottom of the timing cover. When I installed the 1968 400 in my '57,the same mount fit my new engine,making that part a bolt in. The rear of the engine used an iron bellhousing with mounts,also similar to the Chevy V-8 set up,only with the early Pontiac block pattern,which changed to the BOP pattern in '64. I was unable to find an iron bellhousing with the mounts and the later block pattern,so I made a plate to fit the original mounts and fit between the bellhousing and the transmission,and I used a standard aluminum Pontiac manual bellhousing;not the strongest set up,but I haven't broken it yet,and I've given it reason to break.

I've seen larger TF trucks (bigger medium duties) for sale that had Buick motors. And that age would place those motors in nailhead territory.

Mike Boteler has two Buick powered trucks.

The 322 cubic inch engine that was listed as an option for the larger Task Force trucks was a Buick engine. Not sure if this is considered a nail head or not.

The 322 engine was used in the Buick passenger car from 1953 through 56, in several HP ratings. Yes, it was the "nail head" design, with the vertical sides on the valve covers.
Jerry