this may be a dumb question but how can i identify my engine. i was told it was a 312. in the repair manual it says the casting number begins with ECJ. where is this number found. the engine has a holley 4 barrel carb but it isn't the original. is there any other ways to identify a 312. thanks guys.. skip
272, 292, & 312 can not be told apart while still in the car, with the trans and fly wheel off you can tell a 312 by the 1/2 moon cut out in the crank flange.
I believe the half moon cutout is on all cast Y cranks. It is there because of needed clearance for the drill to hollow out the crank throws. But opposite the cutout is a recessed cast area, and in the middle of the cast area can be one small dot, two small dots, no dot, or one larger (about 5/16") dot. The larger dot designates a 312 crank. This would be visible with the clutch cover or the auto trans front dust cover off.
John
thanks for the fast replies guys. we will be looking for that dot real soon. skip