RE: Saito Velocity Stack Test
Hi Rob. I think the GK versions come with the stack and it is an optional accessory for all others. The smaller Saitos all use one stack, and large ones the other, probably both of your engines taking the smaller one. The part number for yours should be SAI50GK93. You'll still have to find an o-ring and I have a couple of spares which I bought at Tacoma Screw Products.
Ernie