Chevy I6 casting numbers

I know this has been done a lot but I can't find the numbers on my block in any data bases
0706485F55Z
Thanks for any help
Josh

 

Have you looked here? http://www.inliners.org/casting/numbers.html
or here http://www.inliners.org/becks/BCN2.html

 

That's not a "casting number" but rather a stamped engine I.D. number but it tells you just about everything you need to know:
It's a full-pressure oiled, 235 with solid lifters, built in Flint, MI in 1955

Good motor!!!

 

Z means 115 hp std shift, Y would be a 125 hp Powerglide.

 

thanks, so in other words its definitely not stock in my '53

 

Nope, it's a good upgrade. The stock '53 had a 216 "splash and drip" motor.