My '84 F150 4x4 finally gave up the ghost, not mechanically but structurally. So the engine (351W), transmission and transfer case have been removed to transplant into an F250 4x4 with a very weak 302.

My problem on the 351 is with the exhaust manifolds; both are trashed, one cracked and the other with a broken ear. New (Chinese) manifolds are about $170/set and are rumored to be of dubious quality, prone to cracking in short order. Shorty headers are about the same cost. The F250 has true duals with no cats so it is a fairly free-flowing exhaust and it would seem to be a good candidate for the headers but I have read on here that they make changing spark plugs more difficult.

Are there any good quality manifolds available or is any brand of shorty headers better for spark plug clearance? Any and all advice to solve this problem is appreciated.

 

No one knows of a decent source for cast iron manifolds? Junk yard manifolds would already be a minimum of 20 yrs old and not the best choice I would think.

How about experiences with shorty headers? Anyone have a brand that they don't find overly troublesome? How about brands to definitely avoid because of spark plug clearance?

 

You should talk with Bruno2. He has a set of headers on the 351W in his Bronco and tells me that the spark plug clearance is fine. I know that we had absolute fits getting the plugs in initially, but that was due to the thick copper gasket he used, and once we got it cut back he says changing plugs is easy.

However, I haven't seen hide nor hair of him of late. I'll send him a text message and see what's going on and if he can chime in on this.

 

If you still have the 302, you could try those manifolds if they are any good. The outlet comes out just a smidge different, enough to mess up the original y-pipe fitting, but since you have dual exhaust it may fit up ok. It will bolt right on the head, no difference there.

 

Dave - I'd rep you if I could, but you know the drill. Anyway, good thinking.

 

I'll give that a try although one of the 302 manifolds has what appears to be a crack but we'll have a close look when the 302 come out. We are just prepping the 351 right now. Then we'll pull the 302 and see how those manifolds look.
Thanks for the feedback, guys. Anxious to hear what Bruno2 says about his headers.

 

I've had no issues with my plugs on the M block with long tubes. Seems easier to me actually. I think Bruno can give you a better vote on the Windsor headers. I'm going to have use shorty headers on the Nissan swap

 

Dorman has them.
got some a couple years ago.
Autozone

i used 302 exhaust manifolds on my 351w.
yeah yeah I know.
But I wanted the smaller diameter
manifolds to keep the velocity up.

 

Dormans are the ones that I heard had questionable quality control. I'm really leery of imported Chinese car parts. But I guess if we couldn't get Chinese parts for these old trucks we might not get parts at all. Sounds like yours worked O.K.

 

Manifolds are the same diameter. That's because the 302 and 351w use the same heads. The only problem is the outlet has a little different angle to it, just enough where the factory y-pipe won't fit.

And you also had to figure in the heat riser thing. If the manifold has one, you have to move it over with it. If it doesn't have one, you can't add one.

 

I have headers, and changing the sparkplugs is about as easy as the factory manifolds. AVOID the Hooker long tube headers part #6912HKR if you have a C6 transmission! the drivers side header will point inward a little towards the transmission, and when you put a pipe on the header. The shift linkage will hit the top of the pipe and not let it drop in to drive. The passenger side header makes it about 3MM's away from being impossible to take the servo piston out. Just my thoughts about the headers thing.

 

Thanks for the reply. What type headers do you have, long tube or shorty and what brand?

 

I have Hooker long tube headers part # 6912HKR and I wouldn't recommend those. Fitment issues on the bottom end, sparkplugs are easy to access. Makes it 3MM away from being impossible to remove the servo piston from the C6 transmission, and the drivers side bends in a bit so when you put a pipe on the header the shift linkage off the transmission hits the top of the pipe by the time you get to neutral. I'd recommend shorties honestly. People on here have heddmans and say they fit fine.

Apparently I repeated myself. Typical when I feel so crappy I can barely think.

 

Sorry you feel bad: nothing serious, I hope. Thanks for the info.

 

Just health problems, and any time!