046 D Cylinder Question

[davidtown]

I have an 046 and it is a D cylinder. Researched a bit but still have a few questions.

Are all D cylinders equipped with the desirable transfer ports?

Can you guys tell from the cylinder or do I need to take measurements?

SN is x 135025668
Muffler is dual port and looks factory.

Pics attached.

Thanks and be well
Dave

 

[davidtown]

More pics

 

[drf255]

You’d have to time it. My understanding is that the very short blowdown jugs were the best. Some with only 14-16* from the factory.