Where abouts is it on the left(low,mid,high) I've looked all over the driver's side but what with the exhaust manifold and inner fender it's pretty tough to see.

Driver's side front, top of block, above the power steering mounting area. Where the head meets the block on front of the driver's side. There is a machined flat surface area with the engine code. If the machined flat area has no code on it, usually means the block has been replaced. Also the engine has a casting number on the lower block area above the pan mounting machined area on passenger side mid area to back. Hope that helps.

It is easiest to get under the truck and look directly under the drivers side manifold under the middle of the manifold. The engine displacement will be stamped under there. Like the previous post said there are other areas to find it but this is the easiest way to find it.

ive always had good luck looking at the balancer to tell if its a 318 or 360, assuming its still in the truck.