Tuning gods- mainfold primary diameter, ashley rally....

[Supercharged Nat]

Hi guys i need to know the primary pipe diameter of the Ashley 'rally manifold' its the 3 piece, 4-2-1 with a 2.5" outlet and, is that inside diameter or oustside?

its the one used on escorts btw for the pinto.

 

thanks!!

[Supercharged Nat]

my bad, i think its actually a 2" outlet!