I'm not sure you can mill the mounting flanges on the fentons so that they are all of an equal thickness amongst them selves or the same thickness as any of the offy mount flanges. Plus there are tabs on the outside tubes of both the offy and the fenton that probably are different heights. On my Fentons, the mounting flanges were not all of an equal thickness.

I don't think its a problem to grind the back side of the flanges to match the flange width of the offys.

I also don't think milling just the mounting surface of the fentons so that they will mount with a slight downward angle will cause a problem with your throttle bellcrank or the linkage to the dual carbs.

The deal with the zinc plugs in the bottom of the offy is that you should remove them, replace them with aluminum plugs and have the aluminum plugs welded into place. The Stovebolt engine company ships their Offys with the plugs welded, I don't think Patrick's does.

If you got the Offy from Patricks and havn't touched it, I bet you can return it and apply the credit towards the purchase of other merchandise from him, like one of the new Fenton intakes.

If you decide you want to get rid of your Offy intake, I'll take it off your hands for $20!

'51 Chevy 1/2 ton w/'62 261, HEI, offy, fentons, dual carter/webbers, t-5 & 12 bolt posi