I'm not sure of the ring pin location or deck height differences, if any.

And just because you "can" do something doesn't mean you "should". You already wasted time and money on a NOS piston.

My advice is to buy the correct OEM parts and use a machine shop that knows these machines and will precision bore and hone to correct factory clearances... Bill Bune is often recommended.

Cutting corners on a piston is false economy.

Thanks Ill do my best to get the right parts.
I don't feel as though I have wasted too much time, money or effort on this bike yet, I'm still having fun.
My Machinist is in his 70s and seems to know what he is doing with 2 strokes, but I will consider mailing it out as well,
Thanks again

I've done it but not recommending it--well not what i did. I set the piston at bdc then felt penned the inlet port shape onto the back of the piston skirt so the top of it was high up under the ring land. Cut the shape out & though Bugger, that's too big from a piston strength point of view. Now i'm worried i'm still using it. I'll see if i can find it for a pic. RT2 that was but same at DT360A in that respect.

I get it.

On the machinist, there are good ones out there. The ones to be wary of are the shops... some with a lot of experience... who see an "air cooled two stroke" and "add a couple of thou" to the factory clearance specs thinking they are doing a good thing and helping prevent a seizure or something...

Seen it too many times... you end up with a top end that rattles like hell and needs another rebore very quickly.

I find it interesting that yamaha says .0016 to .0018" wall clearance for their 80mm bore, that is pretty tight compared to my suzuki ts400 i just did which was .0029-.0033"
I think yamaha was able to make better quality pistons and control the size better.

Note that Yamaha specifies measuring the piston about 1/2" (13mm) up from the bottom of the piston.

Suzuki TS400 piston is measured a full 1 3/4" (44.5mm) from the bottom of the piston.

Piston taper makes it smaller at the top than the bottom so details like where the piston is measured are as important as the clearance spec.

(Suzuki measures theirs abnormally high)

Paying attention to the details is what makes the difference...

ahh yes, the higher measuring point explains it.
my comments on Suzuki's pistons was because I have a collection of about 20 NOS standard ts400 pistons and I spent the evening micing them up out of curiosity
I found some as small as 81.73mm and biggest was 81.96, measured in the Suzuki spot vs the Yamaha spot some of them gain up to .05mm in size while others get smaller or stay the same.
Too bad I don't have as many Yamaha pistons to compare, I think only Enduronut can comment on the quality of the Yamaha ones hahaha!

Wow! That is a lot of pistons!

I have a small collection of new Suzuki pistons. Most are oversize and all are still in the original boxes. I will have to look and see if there are any unusual size or ID markings on the boxes and measure a few sometime.

I know manufacturers make changes to designs... sometimes subtle and unannounced... hard to know for sure if differences found are "quality" or "intentional".

I know that with standard pistons Yamaha graded them carefully and had several slightly different diameter "standard" sizes... and then selected a piston to fit the bore. This is a practice still in use on modern plated (Nikasil) cylinder bikes where cylinders and pistons are size graded A, B, C, and D and the piston is matched to the cylinder.

I don't recall the new standard size Suzuki boxes having distinct actual size (94, 96, 98... equal to 65.94mm, 65.96mm, 65.98mm for example) measurements like Yamaha had on the piston?

Maybe Suzuki final-finished cylinders by hand to match pistons like you would with a re-bore?

I have seen new OEM oversize Yamaha pistons vary ~ 0.0005" to almost 0.001" from each other. Happened on one of my RD350's years ago. I had a pair of NOS pistons and rings in Yamaha boxes that came with the bike. Machine shop told me they were 0.001" different... So I bought another NOS piston and it was closer to only 0.0005" different... right in between the two I already had. I used the smallest pair and the machinist marked the cylinders and pistons "A" and "B".

I also weighed the pistons... they were really close... if I remember correctly, the biggest one was actually the lightest one. It also came in what looked like a newer box than the other two.