Drilling Magnum heads for LA intake pattern

[gagembassett]

Who here has drilled Magnum heads for the LA-style intake bolt pattern? Does anyone have a link to a possible template to do so or have advice on how they told the machine shop to do it? Now before you ask why, it's for IMCA and USRA dirt oval track racing where they only allow factory lowrise 2 barrel cast iron intakes OR Edelbrock 2176 or Weiand 7545/ 8022 and you guessed it, they all are LA style bolt patterns. I already have my 318 magnum built for a high-dollar stand-alone figure 8 league but I switched so now I have to backpedal to more straightforward rules and drill my already prepped magnum heads for LA pattern. Thanks in Advance!

 

[AustinGriggs]

Magnum intake drilling plate project

 

[MoparLeo]

I would modify the intake manifold holes before I would do the heads. Manifolds are much cheaper and easier to do since you aren't doing any thread tapping.

 

[Brooks James]

I've been following this idea. I'm going to airbrush paint into the la pattern manifold holes while it's sitting on my magnum. Then pull the manifold off and the paint will show where the holes should be drilled. Make up a jig to to hold it in place. Punch the center of the holes and drill them out, then tap the holes. If I'm off a little I'll hog out the manifold bolt holes a little.

 

[MOPAROFFICIAL]

Magnum ports are shorter/ less tall in general. So I hope the heads are opened up the LA gasket as well.
As for the intake drilling idea... you would want some aluminum pipe, like thick..and at the correct angle welded on then drill through as a guide.

 

[DNasty777]

As linked above, we had a jig setup to drill the LA pattern, all you had to buy was a brass union to use as a guide and the correct drill/tap set if you didn't have it. Unfortunately they've gone missing. I think another member was working on making another set.

 

[Tbro]

Get a crosswind intake with both patterns

 

[92b]

Who here has drilled Magnum heads for the LA-style intake bolt pattern? Does anyone have a link to a possible template to do so or have advice on how they told the machine shop to do it? Now before you ask why, it's for IMCA and USRA dirt oval track racing where they only allow factory lowrise 2 barrel cast iron intakes OR Edelbrock 2176 or Weiand 7545/ 8022 and you guessed it, they all are LA style bolt patterns. I already have my 318 magnum built for a high-dollar stand-alone figure 8 league but I switched so now I have to backpedal to more straightforward rules and drill my already prepped magnum heads for LA pattern. Thanks in Advance!

7545 is no longer allowed in IMCA.

 

[Brooks James]

There is a template owned by a member, he loaned it out , not sure he got it back. It appears that its possession was shrouded by controversy

 

[Ceedawg]

I have my template done, all you need are drill bits and taps, but I get $200 up front to send to your address, when I get the template back I’ll refund your money less shipping. It comes back to me not another member. That makes both of us honest and if the template goes ‘missing’ I have enough money to make another. Trying to correct the problem with the other members template.

 

[DNasty777]

I have my template done, all you need are drill bits and taps, but I get $200 up front to send to your address, when I get the template back I’ll refund your money less shipping. It comes back to me not another member. That makes both of us honest and if the template goes ‘missing’ I have enough money to make another. Trying to correct the problem with the other members template.

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@markmopar

 

[RustyRatRod]

There is a template owned by a member, he loaned it out , not sure he got it back. It appears that its possession was shrouded by controversy

It was outright stolen.

 

[67Dart273]

I have my template done, all you need are drill bits and taps, but I get $200 up front to send to your address, when I get the template back I’ll refund your money less shipping. It comes back to me not another member. That makes both of us honest and if the template goes ‘missing’ I have enough money to make another. Trying to correct the problem with the other members template.

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How does this index accurately to the head?

 

[DNasty777]

It was outright stolen.

Yupp. Total deadbeat taking advantage of the generosity of others.

 

[pittsburghracer]

Is this piece of crud still allowed on this website. Man I hate thieves.

 

[Ceedawg]

How does this index accurately to the head?

Using dye scribe a line dead center of bolt hole, the template is marked for that. At the bottom of template I have a stop to lay against the intake face bottom edge. If head has been milked then a shin of same thickness taken off can be added or just ream the intake hole bigger. I used vise grips to hold template yo head. A lot more to this process to make it work.

 

[Brooks James]

looking good cant wait to see the final product

 

[Ceedawg]

looking good cant wait to see the final product

You mean the head?

 

[67Dart273]

Using dye scribe a line dead center of bolt hole, the template is marked for that. At the bottom of template I have a stop to lay against the intake face bottom edge. If head has been milked then a shin of same thickness taken off can be added or just ream the intake hole bigger. I used vise grips to hold template yo head. A lot more to this process to make it work.

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Thanks!! Seems to me that using a "virgin" OEM LA head I could make one fairly easily. The center mark seems like an easy means

 

[Ceedawg]

Thanks!! Seems to me that using a "virgin" OEM LA head I could make one fairly easily. The center mark seems like an easy means

Possibly but intake can’t move plus you need the bushings to align the drill bit, then how would you drill the two center ones? If you sawed off the head side of an intake then you’re right where my template is less the guides and sleeves so...
And I did use a virgin LA head, a J head, to make up the template.

 

[RustyRatRod]

I guess I'm just stupid. I don't see how that attaches to the head.

 

[Ceedawg]

I guess I'm just stupid. I don't see how that attaches to the head.

I don’t have the pic of that but i can get it. I welded a 1/4” rod at the bottom to lay up to the head to align it square to ports then simple vise grips to hold it in place. I did two holes the used bolts to hold it but not needed. It’s aligned side ways with the scribe line off the existing bolt holes (LA and Magnum are the same spacing)

 

[RustyRatRod]

I don’t have the pic of that but i can get it. I welded a 1/4” rod at the bottom to lay up to the head to align it square to ports then simple vise grips to hold it in place. I did two holes the used bolts to hold it but not needed. It’s aligned side ways with the scribe line off the existing bolt holes (LA and Magnum are the same spacing)

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Ok, my dumbass mind was tryin to think how it bolted to the head. LOL I got it now, said the stupid one.

 

[Ceedawg]

Ok, my dumbass mind was tryin to think how it bolted to the head. LOL I got it now, said the stupid one.

More pics, AND both bolt patterns can be used if one finds a good Magnum or LA intake. Those sleeves are 4130 CM so they won’t wear as fast

 

[67Dart273]

What I was thinking of doing:

1...OEM unshaved head for "jig" oh wait you can't SAY that,
2...Make the blank plate and index to head surface
3...Make at least 2 studs in lathe, grind to points for centers
4...Install studs in heads, install plate and tap to obtain bolt centers
5...Drill small pilot on these centers
6....Install in drill/ mill ream to clear bolts
7....Install plate on head using these holes with bolts and obtain centers for remaining bolt holes, drill small pilots
8....Ream all holes to clear intake bolts
9....Install plate and pilot tubes on head with long bolts to clamp and weld pilot tubes.

So the flaw I see? is that the tubes will now be large enough to clear the intake bolts, rather than the drill size for the tap. This can allow some slop, BUT you can buy thin wall tubing (brass?) which might be a work-around, inexpensive, and easily replaced when worn.

Maybe I could ream and install helicoils in the head to accept 5/16 bolts and that would then allow me to use 5/16 bolts to "jig" the thing together