I picked up an unknown cady that I'm slowly trying to figure out what is in it. I was told 1969 500. Obviously not right. The head casting number is 1486250. I did not find this number in Big Inch Cadillac nor MTS tech manual. I did find in a search the claim it is the 68-70 small chamber smog. It does have the EGR hump down the middle. It had someone's rendition of a shaft rocker assembly. Does anyone recognize it? Lastly, I wasn't expecting the above so now I'm curious what camshaft is in this sucker. Is there an easy method to spec a camshaft?