Piston direction???model D

I have a new Gol piston for my model D I have also had my barrel rebored to match I was just looking at reassembling it and I noticed there are no marks on the piston with ref to which way around to fit it? ( i.e towards the exhaust). I have checked the ring pegs and they run with out going over any of the ports either way around you fit it with the same amount of clearance between the ports so should I fit it with the ring gaps towards the front ( exhaust) or the back ( inlet ) or doesn't it matter ?
My thoughts were towards the rear (inlet) cooler ??
Is there a thrust side ?
Thanks again for any help
My thoughts were towards the rear (inlet) cooler ??
Is there a thrust side ?
Thanks again for any help