Technical 401 in a 49-51 merc

My avatar has a 425 nailhead with a nova subframe graft I had to makes headers for it, I have another 49 merc with a stock frame and a 401 for which I am making headers for as well. I am planning a third 49 Merc with a 401 and a stock frame. I am wondering if any one makes headers that fit this application cause they are a lot of work to make. Has anyone ever fit 322 manifolds to the large port heads successfully?

 

I would venture a guess of no to the headers. I’ve made all the headers for my mercs and other builders too. I think on a Buick motor it would be a long shot.

 

it's a narrow engine--should be plenty of room.

 

322 is narrow, 401 425 not so narrow.

 

Check out Patriot H8500 headers. There may be interference with the steering box though. Good manifold candidates are 1960 LaSabre 364 single exhaust driver's side, and 1961 LaSabre 364 single exhaust passenger side. Both hug the block pretty tight, dump in the center, and match the 401 ports. I have those on my 401 going in a 40 Buick. Left and center in the pic.

 

Thanks bgt, the hunt is on.

 

There is also another manifold that may work on the passenger side. It leans back about 30 degrees which puts the pipe going beside the oil filter. It has a fairly large "plenum". If you have room on that side, I have a spare, along with an assortment of other nailhead manifolds. PM me and I will send pics.