Early and later timing cover/WP have fan in same place?
 

Does the fan stick out the that same distance from radiator on early and late 8 bolt vs 11 bolt setups?

late model distance from WP hub to font of block where timing cover meets it 7 3/16". 65 GTO 389 6 5/16" so almost an inch shorter!

Skip,there is 2 diff length 11 bolt water pumps.Dont remember the exact diff.I know someone will have it.Tom

Early 69 is 4", late 69+ is 4.5"

Late assume for a 78 motor

I'd say the difference is close to the stated 1" difference. Things get a little tighter when the engine is swapped to the later 11-bolt setup. On the '65 wagon the severe duty fan clutch ended up too close to the new Cold Case radiator so we went to the trouble of moving the radiator brackets an inch forward. I believe that Hayden now has a shorter shaft version of their severe duty fan clutch that would make things easy.