Offy Manifold

[HighVolkage]

Will the Offy tripower 5970 fit a 78 200 head (D8BE)?

The guy at the machine shop says if he mills it to fit it might make the log too thin I guess...

 

[KustomSkylark]

Offy makes one for the earlier heads and another one for the later heads.

 

[CobraSix]

SO long as you get the one made for you year head, you'll be fine.

Slade

 

[KustomSkylark]

go to this link and at the bottom of the page you can download a current Offy cataloge and it will have the part numbers you need. Also Dan, the guy who's website it is, is very good to deal with if you decide to order something from him.

http://www.exeterautosupply.com/

 

[powerband]

As far as I've seen, there are two Offy setups still available. The "early' on will fit the round intake heads up through @ '68 C6xx (?) . The "later" one will fit the C9xx '70 head through @ 1975 (don't know) . I have a "later' setup that will not fit the D7xx head without some minor modifications as the center flange/bore is not same height as early 70's heads. I think they call the the early 70's the "flattop" manifold runner head and the late 70's the "Octagon" manifold runner.

I have a later Offy setup and tried it on both the early 70's head and the later'70s head and it fit right on the early manifold runer but the later one was not a bolt on match but not too difficult to adapt. . My age and distractions cause me to be fuzzy on the exact difference.

Powerband 8) :roll:

 

[mustang6]

Your mechanic is right to be concerned about milling the top of the log too thin, he does need to be careful. I had an early 70's flat-top log head and when it was milled flat the metal left was only about 1/4" thick. The Offy setup included studs for attaching the ends of the manifold, but since there were so few threads for them to bite into with only 1/4", I used small bolts threaded up from inside the log to strengthen those attachment points.

 

[CobraSix]

My Offy manifold I think was a little older and didn't mount studs to the log. It basically had you cut out the web flanges and you did no milling of the log:

http://www.kastang.net/offenhausermod.html

Slade