rjtechx ( Feb 2007)
///////I'm putting a 289 engine back together.  The pistons are aftermarket of
unknown brand. They don't  have the T-Slot in the skirt that the
originals have. The shop manual gives you the slot in the skirt as a
reference to installing them. However they do have a hole drilled on
the top of the piston marking the piston for the front I'm assuming. I
need to confirm that this is in fact the front.
When I disassemble this engine one bank had the hole towards the front
the other bank had them to the rear. The pisons look identical front to
back, the only difference I see is the oil holes for the wrist pin are
at a different angle if all pistons are indeed installed with the
drilled hole toward the front.
Thanks//////



All the holes to the front, but make sure you have the rods installed correctly too.


All rod oil holes should point at the cam

Be sure to instll pal nuts :-)



It's generally 0.0015 - 0.002 per inch of piston diameter.  So if your
piston is, say, 3-inches diameter, it would be 0.0045 - 0.006 total
clearance.