Haha, yeah, that thing has been in the "coming soom!" category for years. I did some searching last night and you're not the only one looking for one. The word is that they don't make a tunnel ram for 351w. I don't see why not though, considering they have them for 302 and 351c engines. You could do a sheet metal intake.
I had a sheet metal tunnel ram built by T R E in Tenn.Look at Hot Rod mag, sept, 2006. The wookmanship and quality was very good. I was able to make 816 H P from 374 cubic inches.Very trick piece. JOE SHERMAN RACING
At first glance it looks trick. The runners a WAY too long for any high RPM engine. It could be modified to work better. I have some other One of a kind manifolds that will never work correctly. JOE SHERMAN RACING
To be honest, if you think of the width of the carb pad (unless it's dual dominators, but that doesn't look like a dominator flange pattern to me), that intake's nowhere near wide enough for a 351. That's a 302 tunnel ram I'm 99% sure. Maybe someone should pay the 700+$ and buy it to see =p.
Theres a lot of things I could do once I win the lotto. I just spent the better part of a day making a 6 pinion planetary for a C-4 . I can buy those too but its a lot cheaper to make one. I can make a manifold. It'll just take a few months.