There is absolutely nothing wrong with using a floor sitting 36" belt sander. Read my post above, nbr 17. You aren't surfacing a cyl. head. Just use your straight edge and some bluing or slightly spray it with some paint. Just take it slow and set the manifold back on the sander flat. The machine shop wanted to much to build a jig to hold the manifold. I did another guys car this way and both have done fine with absolutely no issues. I also refresh the surface of the turbo flange and where it mounts to the manifold surfaces when I have them apart for any reason, no big deal.

I doubt the OP has a 36" belt sander or a mill, if he did this thread probably wouldn't exist.

That works if it's a good belt sander (a real one like you say, big and flat) and the person using it knows how to use it. I've surfaced things myself too, so I know it can work. Still having it machined flat would 100% for sure result in it being flat, having it belt sanded somewhere will 100% make it shiny, and maybe flat depending on the shop and operator.

Reread his post. He said he was going use a belt sander and you and a few others said that wasn't a good idea, so evidently he has access to one. Alot of people have them in their garage as they are handy for alot of other things and they don't cost that much at HF. IF he has the skill, it is as good as way of doing it and it is free. It ain't brain surgery. My post was to let him know that his idea of doing it that way is fine and has been done by others and it WORKS. Have a good day.

He also said he was being sarcastic about using a belt sander in post 5.

Anyways, we agree it can work. I hand-surfaced turbo flanges, and every cylinder head on my car, including on the one on there now at 28 PSI. I know it can be done and work. If you know what you're doing and have the right equipment.