LA intake to magnum head ??

[DionR]

The OP has a old LA Offenhauser intake that he wants to bolt onto Magnum heads. That old intake doesn't have bosses for vertical bolt holes so the heads must be re-drilled to make it work. The Crosswind intake the guys are talking about has bosses for LA and Magnum bolt holes. (bosses for fuel injectors as well)

He also said he has a crosswinds intake in post #8 and then said it had a dual pattern in post #19 after stating it is an old offenhauser intake. I am confused because the OP has contradicted himself several times, not because I don’t understand the problems of mounting an LA intake on Magnum heads.

 

[Professor Fate]

OK, the intake is dual pattern, when i put it on i dont remember seeing la bolt toles in the magnum head

If it's a 1960s Offenhauser dual quad like you say, I guarantee you it isn't "Dual Pattern"- there weren't Magnums then.
And no, you didn't see any LA pattern holes in the Magnum head, because there AREN'T ANY. You have to drill the head yourself. That's what the jig is for.

 

[mopowers]

Has this thread given anyone else a headache, or is it just me?

 

[Brooks James]

Post #21

View attachment 1715811871

Creative people can do this drill and tap operation, with the heads still on the engine using some high density foam down inside the push rod runs, a vacuum cleaner, masking tape and some drop cloths.

Carry On . . .

Yes, thatsz my plan at this point im Even might use 5/16 instead of 3/8 so i have a Larger margin of error

 

[pishta]

I dont think its that hard to drill the magnums for "90 degree" intake bolts. just set the intake on the heads and mark where the old holes meet up with the head and drill and tap them. They are not blind on LA's and there probably open on magnums too.

 

[mygasser]

I dont think its that hard to drill the magnums for "90 degree" intake bolts. just set the intake on the heads and mark where the old holes meet up with the head and drill and tap them. They are not blind on LA's and there probably open on magnums too.
View attachment 1715811967

they're not quite 90 degrees on la's though are they? early 273's even less so from what i've read.

 

[pishta]

90 degrees in air quotes.....Take it as a general orientation. The 64-65 273's had a slightly different angle than the later LA and a 5/16 bolt instead of the more common 3/8 bolt.

 

[Stephen Hotz]

I have now run both 360 magnums with the drilled heads. No vacuum leaks.