Also a hearty DOW welcome Matthew.
The primary problem with the F.E.M.A. design is it is a “floating zones” system. Without zone defining air jets; without a constriction all-gasses-must-flow-through zone defining area as you use a FEMA it will zones-float making too much wet, sooty, tars laden produced gasses.
Your picture shows well you are willing to cut, grind, Fab and weld. This is good. You are a NOW-DOer. This is even better.
Actually there are at least three broad ways to woodgas produce for a 350 CID Chevy engine.
Mr Wayne says his DID begin as a FEMA base. Then added air jets. Then added air pre-heating/firetube cooling system. Along the way added-in a soots-dropper/heat-exchanger. Refined out a parallel pathways cooling rack and natural-stem “hay” filtering system.
Really need to buy the book to see all of the devilish-details including engine controls.
Another way would be a S.E Werner/JohanL./Dutch John ash-slope shielding, modified “V” hearth system. These following the well proven out 1940’s-1960’s bases. These have very well proven out zones fixing air-jet nozzle rings, constrictions positively defining the oxidization to reduction zones boundaries. Realistic/proven ash handling grating systems. And more. Again with proven devilish-details work-arounds.
A third way . . . . ha! I’ll let the charcoal-teer’s chime in on their black-magic.
All ways . . . here is where it begins. Your availability, capability to get/make, size process and dry the actual wood fuel.
Without that you ain’t ever going anywhere.
Please show your woodpile now. Or declare your wood species intended. Can you get/process enough to support an at least 2 pounds of wood per mile habit?
tree-farmer Steve unruh