Are they any easily visable ways to tell a truck 348 or 409 engine from a passenger car engine without removing the heads?
For the 1965 #3857656 block, look on the lower front of block on each side of the timing cover. On the left side (right side when standing in front of engine) there are two 7/16″ coarse thread bolt holes which the power steering pump bolts to. These are drilled on all blocks both car and trucks however, truck blocks will also have these drilled and tapped on the right side of the block (left side when standing in front of engine) where passenger car blocks won’t. No bolt holes on that side indicates a car block, with bolt holes indicates a truck block. No car blocks ever came from the factory with these drilled. Note however, someone other than the factory could drill and tap these so it’s not proof positive. ***This has to be checked on other truck blocks so it may or may not apply to those. Back to the top Q: What kind of Crankshafts do the 348 and 409’s have? A: All of the 348 and 409’s have a forged crankshaft. Visually, you can tell them apart by looking at the rear bolt flange. I
