i have a 70 el camino and need to know if my engine is original. the # on the intake is 18436672. i cant find a number on the block, any one know where i can find one?

www.mortec.com

http://www.yearone.com/updatedsinglepages/Id_info/gm_engine_id/gmidimages/endinedetail1.jpg

Engine casting number should be 3963512 (454), 3969854 (402), 3970010 (350), or 3970014 (307) - you didn't mention which you had, or should have. The number you supplied on the intake is actually the engine's firing order, 18436572.

Need more information about the El Camino: it is suppose to be an SS; when was it built, etc. It'll help with casting dates.