engine identification

[skip54]

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

[Lou]

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.

[Hoosier Hurricane]

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

[skip54]

thanks for the fast replies guys. we will be looking for that dot real soon.  skip