I was wondering are there any other people out there who has done this swap? If there is are u running headers or stock manifolds? I know that u can't use stock 351M or 400 mainifolds on a 351C because the right hand exhaust port hits the starter. i was wondering if you could use the headers from the 351M 0r 400 on a 4x4 and still have room for the front drive shaft

 

I know you can't use the 351m/400 headers on the 351c. When I
tried a set on my 53 f100, they would bolt to the heads but
the collector hits the 351c bellhousing.

 

I have a set of headman headers on my 79 f150 4x4. It has a 351m in it. You will have to drop the front driveshaft to install the driver side header & put it back after headers are installed. I race mine,up hills,over jumps etc. & the front driveshaft doesn't hit the headers. Hope this is helpfull.

 

There is a pair of what they are calling HO headers on ebay that might work, I really don't know for sure but you might check them out.
Search for item # 1812085672. they are not mine and I have no association with the seller. Just saw them and then read this post.
Hope this is of some help.