I did a search. I read a bunch of stuff but all I could find out was that they are different, and you can't swap them. can anyone tell me what the differences between them are? I know about the butterflys, but otherwise, I'm pretty ignorant. specifically, I'm concerned about where they meet up with the head. so basically, head stud location, runner size, and runner location. If one of them is definately better from the factory, which one?

possibly going onto a F series motor.

 

honestly both manifolds don't perform very well, but they work. the h22 manifold would deffinately be the better performer between the two. i believe the only difference between the two is the runner crosssection. where the h22 is larger.
i'll take a closer look at both when i go by the shop tonight.

 

anybody else?

 

as far as what people have said in the past is that from the butterflys up is the same, even the throttle body, and the only difference is the bottom half that bolts to the head.

 

its all the same throttle body... no need to change or anything, caues a HUGE hype over it

 

the flange is different between the h22 and the h23. the EGR port is different and I think that coolant goes through the h23 manifold near the EGR port. bolt pattern is differnt too. HTH
the Pirate

 

yeah thanks that was exactly the kind of stuff I was looking for

I guess I'll just end up buying both IM gaskets, since both of them will have to be modified.

 

Bolt Pattern, Flange AND port spacing are different

I don't think you can do it. Besides there are ones on ebay right noe for cheap!