Yamato 80 megaphone measurements

[Albert]

Would any of you fine folks happen to have a stock 80 expansion chamber/megaphone laying about and could measure. I have the upper aluminum manifold but I need to know total length and the diameter at the bottom of the pipe.

Thanks

[ZUL8TR]

P Meg overall length 10.625 ±0.062
P4 Meg. Small Dia. 1.614 ±0.050
P5 Meg. Large Dia. 2.598 ±0.050

Info here pgs 78 - 83:

https://www.apba.org/documents/13180...l%20Manual.pdf

[Albert]

Thank you, never even thought to look in the rule book. This spec racing stuff is new to me.