The rectangular piece is the jamb. Notice the slot? It's for a positive fit. Use Oak or similar hardwood. Aluminum or steel will do also but take longer to make than wood. Oh and do not disconnect fuel line as suggested . Not only will you still spray lot's of fuel out the holes from the fuel that's in the IP. You will then have to do more work to bleed the air out.
Jammed in place. Make it fit tight.
