[56EL]

I have a small block in my 56 but I am not sure which one. I cant see any numbers except the one on the pad in front of right head. It looks like 10609 cgr. I have found the cgr code but it shows up for a 70 -71 z28 350 and a 70 71 truck 400. How can I tell which it is? Thanks Curt

 

[Will]

A 400 will have 3 frost plugs on each side (1 in area of side motor mount) all others sbc's only have 2.