Exhaust manifold size?

[grundig]

Hello,

My '70 F250 (2WD, 390, C6) has a badly cracked manifold on the driver's side that needs to be replaced. I notice there are two different sizes for these manifolds--one with a 2" opening and one with a 2.32" opening.

This may seem like a stupid question, but is there any way I can tell which one I have before I take it off the engine? To minimize my down time, I'd like to order the replacement while I'm prepping the bolts/studs over the next couple of weeks (using the recommended combination of peanut butter, weasel whiz, and voodoo.) I assume it's a 2" because I measured the outside diameter of my downpipe at 2 1/4", but I'm not 100% certain on this.

Any help you might offer would be welcome. Thanks.

[fordman]

its a truck only manifold. it can be replaced by any truck manifold up to 1976 when they stopped putting the fe in trucks. the 73 manifolds for the drivers side was changed to look like the pic i posted. i had my manifold welded by my dad years ago when it cracked. he left it on the engine to do the first weld and then took it off to weld the back side. i dont know the hole size but 2 inches sounds right to me. the pipe size is 2 1/4. who wants to know the size? they shoul dknow the correct size if you are ordering it from some place. ebay has those manifolds as well as the vendors should also have them on the links page. www.fordification.com/links.htm as well as www.rockauto.com

[grundig]

Thanks. My bet is it's a 2" as well. I wanted to know to make sure that I ordered the right one. But...it looks like I have access to a manfold from a 352, so I'll try that and see if it's the right one.

Any suggestions for a good source for replcement bolts/studs/nuts?

[sideoilerfe]

It should be 2.25. All of mine are.

[fordman]

as far as replacement bolts i think i like the idea of stainelss bolts. if you break any of the olds ones off in the head then you'll have to make a decision on what to get at that time.