Hi everyone !

I was attending a car show on the week-end when I was asked about the «Buick 401 c.i. V-8 nail-head engine».

Would anyone have any info to share on the subject ?
Your responses are appreciated. Thanks !

Serge from Montreal, Canada

There were various Buick nailhead engines made from the mid-1950's until the last year, 1966.

The 401 was used in the 1965 and 1966 Skylark Gran Sports, and probably some larger models.

They got the name due to the valve covers being almost vertical to the block.

There is a ton of information available. Try going to www.yahoo.com or www.lycos.com and searching on "Buick nailhead".

What info for the engine would you like? 445 ft/lbs torque, 10.5/1 compression, 325 hp

53-66 was the nailhead.the early models from 53-56 i believe were the 312or 321.then there were the 364-401 and 425 which were very much alike and lots of the parts were interchangable.59-66 was the 401 and 64-66 was the 425.only differences is bore on the 364 -401 and 425.in 67 the made the 400 and 430 to replace the nailhead.i heard that the reason was b/c of the insurance companies having gripes with the motor as far as insuring cars with the infamous nailhead.the reason they are called nail head is b/c of the small diameter of the valve stems.very easy reconizable by the vertical valve covers.hope that will give you a little more insight.
Ryan