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Holley 390 to Offy 360

Posted: Tue Sep 25, 2007 6:16 pm
by sean
Well not being able to afford the Edelbrock 500 bits and bobs I have elected to go the above route. Hmm!! Now I need to find the adapter plate that mates the two together, having got the carb and inlet manifold sorted. Any suggestions, anyone as to where I might get one?
Also does nayone have any thoughts on their experience of this setup on their 3.5 or recommendations?
Thanks for any help.

Re: Holley 390 to Offy 360

Posted: Wed Sep 26, 2007 5:09 pm
by Paul B
sean wrote:Well not being able to afford the Edelbrock 500 bits and bobs I have elected to go the above route. Hmm!! Now I need to find the adapter plate that mates the two together, having got the carb and inlet manifold sorted. Any suggestions, anyone as to where I might get one?
Also does nayone have any thoughts on their experience of this setup on their 3.5 or recommendations?
Thanks for any help.
You can buy ready made adaptors from Summit, to match the carb to the manifold. I made one myself from 1/2" as I'm a masochist like that . :D

Posted: Thu Sep 27, 2007 5:20 pm
by sean
Thanks for that. Never heard of them but I guess a google search should do the trick.

Posted: Thu Sep 27, 2007 5:47 pm
by minorv8
I thought that the manifold has the same bolt pattern than the carb ? Holley and Edelbrock carbs share the same pattern.

Posted: Thu Sep 27, 2007 6:27 pm
by JP.

Posted: Thu Sep 27, 2007 7:09 pm
by sean
Thanks.
No not the same bolt pattern at all. The manifold bolt holes are much closer together than the holley#s mounting hole.

Posted: Thu Sep 27, 2007 9:42 pm
by Pocket rocket
Any chance you can post up a pic , Sean.

Just checked & my Offy (JWR) has 8 holes - thought this was standard

Image[/img]

Posted: Fri Sep 28, 2007 4:50 pm
by sean
Mine has two oval slots and not like yours. The ebay link for it is.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... otohosting[/url]

Posted: Mon Oct 01, 2007 9:15 pm
by sean
It seems it's the wedge plate I need which is proving a little tricky to get hold of. I would have thought this quite standard set up. It appears not.

Posted: Mon Oct 01, 2007 9:44 pm
by JSF55
When i clicked on ur link at the top of the page was a list of simillar items on ebay, in it was a 5 degree plate from paul at V8tuner !
ebay 280154105961

Posted: Mon Oct 01, 2007 10:17 pm
by Pocket rocket
And strangely it's a couple of quid cheaper direct from his website
http://www.v8tuner.co.uk/product.php?id=114

Posted: Tue Oct 02, 2007 2:02 am
by Paul B
minorv8 wrote:I thought that the manifold has the same bolt pattern than the carb ? Holley and Edelbrock carbs share the same pattern.
No, as I discovered after buying a new £220 Weber 500, then having to lash out another £190 for a manifold as it didn't fit my Offy 360 :cry:

Posted: Tue Oct 02, 2007 6:51 am
by CJV8
This is a bit odd as I took a Holley 390 off my Offy 360° and dropped an Edelbrock 500 straight onto the same studs.

Posted: Tue Oct 02, 2007 5:13 pm
by sean
Yeah, I saw the one from V8 Tuner but looking at it I just don't think the holes are far enough apart for the Holley and the Offy. Besides I had actually mailed Paul at V8 tuner and he said it would need to come from Offenhauser, for which I haven't yet found a proper site.
I have a feeling that I may be in a similar position to Paul B.
For what it is worth the mounting holes for the Holley are approx 194mm diagonally and 137nn for the Offy carb mounting holes. The pic of the V8 tuner one certainly doesn't look that far apart.
Agreed! Weird! One would have though it was simple.
I wont even mention trying to get a rebuid kit for the exact carb number. How much can a 390 cfm 4160 Holley really differ?

Posted: Tue Oct 02, 2007 7:58 pm
by JP.
sean wrote:.... it would need to come from Offenhauser, for which I haven't yet found a proper site.
?
http://www.offyparts.com/ its that simple..

Next option, you only need the adapterplate to fit the holley pattern carb on a Offy patern intake. You could take a normal 1" Holley Alloy carb spacer, drill the extra holes for the Offy patern and here's your home made Offy carb adapter. Ohh forgot, you'll need Allan bolds to fit the adapter cause the'll sit in the adapter.