Sorry for the confusion. Here is a picture of the stamping. The buick is a 1955 Century and the engine is a 322 nail head. I have researched and not been able to come up with this stamping. Everything I find says it should start with a "V". Plus even if I think that the i is a miss stamp, I can't match the numbers i2408246. The 6 is hard to see but if you look at the bare photo, you can just start to make it out. If I hold a light off to the side I can make out the 6.

Any help would be appreciated. Trying to determine if I have a special performance engine or what?

Buick started a new engine numbering sequence for the V8s in 1953. This sequence continued on through 1956.

The first '53 number was V2001x where x is a suffix digit indicating the car series. The first '55 number was V720080x. The first '56 number was 1460023x. When the one-millionth V8 was reached in '55, the V was replaced by 1. The suffix digit 6 = Century series which agrees.

We typically see I used for 1 in ID numbers. Similarly Buick would use an odd-style font on the 6 that looks like a b and a 9 that looks like a q. Presumably this cut down on tampering.

Total '55 engine production would be 1460023 - 720080 = 739,943 assuming all numbers were issued. This agrees well with total car production of 738,814.

Your engine would have been built about 70% of the way into the '55 production run.