Not sure why I was so stuck on only putting evap cores in the cowl cheeks.

Evap cores are cheaply available.

I'm thinking they could easily be stacked under the engine as well. (Not making then 8" thick, but flat end to flat end, or tank-to-tank).

One way would be to join them flat end to flat end with an o-ring. That would put them in series. 13" wide and 18" long.

The other way would be tank against tank, which would enable parallel (but more hoses). 9" wide and 26" long.

I don't remember earlier postings on this, but would 3/4" ID hoses be enough for a series configuration? (200 max HP Renesis, more likely 180 HP)

Finn