Drilling magnum intake for LA bolt pattern??

[mopar65]

I just orderd a set of the trickflow heads for my 360 magnum engine. I am wanting to use my indy single plane intake. Its already been ported etc. So I need to drill it for the LA bolt Pattern. Has anybody drilled one with out a template? Could I just lay the intake gasket on the intake and mark the hole ,then drill it that way. Or would I be better just send it off to a machine shop to have done?​

 

[vitamindart]

I think most people drill the heads for both patterns. don't know that other than some of the knockoff intakes I have ever seen dual pattern on one.

 

[Bobzilla]

That is straight up old school do it yourself stuff right there. With care in fitment, there is no reason you can't get it drilled properly. I would do it like you said, just making sure you are careful.
Here is another thread I found with the LA holes drilled in the Indy manifold. Nothing special, except the placement and making sure the bolt head has a flat to rest on after drilling.

indy 360-3r intake manifold plenum

 

[Mopar Sam]

Here you go.

Magnum intake drilling plate project