964 P and C help needed

[Tbone425]

Trying to sort some pistons and cylinders. Bought used off a low mile car, very nice, specked out flawless. He’d to tops head blasted and lost the numbers and E. Only marking on the piston are 100p36 on the inside. Trying to figure out if there is a way to determine orientation. Is the E on the same orientation as the numbers on the inside? Is there a way to also ensure these are 964 and not 993? Pistons (Which would be odd as they came from a Singer donor car). Because, as I understand it, the pistons won’t work with my 964 rods? Thanks to anyone who can shed some light

[Tbone425]

[Tbone425]

Inside the pistons it has “100P36+“

[pocv0]

The cylinders are definitely 964 , pistons as well. It looks like someone machined the crown for a little more clearance under the "2" in the pic. I have a set of those pistons in my shop, I measured them and the crown and valve clearance is symmetrical. I would orient the machined portion up ( intake side ) , seems to make sense. Or they machined a little material off the the top of the piston to lower compression.....maybe.

[Flat6pac]

Those are Mahle pistons.
There is a mark to the flywheel side for orientation much like the turbo pistons have a squiggle line with a point
Bruce

[Tbone425]

Originally Posted by Flat6pac

Those are Mahle pistons.
There is a mark to the flywheel side for orientation much like the turbo pistons have a squiggle line with a point
Bruce

No marks on the crown of these. The soda might have got them. If the Clearanced side is oriented to the big valve the rest should fall in place, correct?

[john walker's workshop]

964 pistons w/100P36.
The squared corner by the pin hole goes to the left on installation.

[Tbone425]

Thanks John/ Bruce/Pocv0!