I have a 1951 Ford 8n tractor with a funk conversion, which means it has a flathead 6 industrial truck engine. I'm rebuilding it since it doesnt work... but I cant seem to find some parts. I need an intake/exhaust manifold, but cant find one. the rest of the parts (i believe) are readily available. Does anyone knwo where i can get one? What about other engine parts? Is one place better or cheaper than another?

thanks,
Brian