'42 46S Engine number ID

[g-g-g0]

My books show that the '42 46S engines numbers are seven digit numbers. I am looking at a car that starts with 447XXXX and then has an aditional 4 about a half inch to the right. Can anyone tell what the "extra" 4 might mean?

Thanks,

Gary

[sean1997]

The 4 means the engine is from a Series 40 (Special). For I8 engines for 1942 and later the first 7 digits are the sequence number and the last digit is the series. For 1941 and earlier the first digit is the series and the last 7 are the sequence number. All 8 digits combined form the engine serial number. I'm guessing there is a space because the series digit was stamped after it was determined what car the engine was going into (40 or 50 series) and the sequence number was stamped when the engine was built.

Since there is no such thing as "numbers matching" for 1956 and earlier Buicks, the only thing you can check is that the series digit matches the car series.