Dunstall 810 pistons which way round ?

Can anyone just confirm my reasoning. On removing the GPM 767 Dunstall pistons on my 810 Commando I failed to mark the "Front" to avoid confusion when re-fitting same. I remember thinking it was obvious because the much larger cut-away on the crown must be for the Inlet valve. However when reading the several different publications on Commandos referance is made to the Inlet valve cut-a-ways being the one farthest away from the edge of the crown!? And DOUBT crept in.
I appreciate the Dunstall piston is a differnt design, please confirm - the Larger valve cut-a-way is for the INLET.
I have re-built dozens of Engines (but not with Dunstall bits) and can't continue with this one unless 100% certain.
Thanks in anticipation, Senior Moments are occurring more frequently. Dave in England. Not many 810s over here.

I just went to look at the ones for the engine i'm building, one cutout is defiantly larger and has the L or R stamped in it. Larger cutout to the intake.

They have a positive rotational orientation. In other words, if they aren't installed correctly, the cutouts don't align with the valves. Front & back are only one way they can go wrong; they can also be wrong left & right.

I have this pair. Maybe the photo helps others see the deep valve pockets.

Thanks everyone,thought I was right but you've all confirmed it. What a great bunch of guy's motorcyclists are. It's 11pm here in UK , freezin cold and I'm almost tempted to go in the Workshop and fit the pistons tonight (but I won't) Iv'e been riding bikes since my 16th birthday and I'm 69 next month. I've ridden hundreds of bikes and managed 25 yrs as a police rider, 20 of those as Instructor. Where ever I go in the World I seem to end up talking to someone about motorcycles. The wife is not impressed as one tale leads to another and before you know it an hour or more has passed. But I love it, and always part company having made another Genuine Friend.
Once Again Many Thanks to All. Dave
Too Many Bikes to Mention !

Common sense ( :lol: ) says , the big cutouts are INLET thus go AFT . The smaller cut outs are EXHAUST , and go outward at the front .

If the gudgeon pin is not central, it goes towards the back.