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Chevy Vortec intake drilling to standard intake

Posted: Tue May 26, 2009 8:56 pm
by af2
I have seen a plate that allows you to drill the standard intake holes. I haven't seen one as of late and need one for my son's Vortec. He found out about ProComp seats dropping!!!! Iron heads even!!! That will be another thread!

Posted: Tue May 26, 2009 9:28 pm
by Keith Morganstein
I have one of the plates. It's BHJ / goodson. It's quite expensive, but works slick.

Posted: Tue May 26, 2009 9:36 pm
by af2
I wish most of you were closer!
Keith, if I can't find someone to do it closer I will call you. The shipping is going to kick my a$$$. :)

Posted: Tue May 26, 2009 10:05 pm
by machine shop tom
I don't like the idea of drilling Vor-Tec heads for earlier style intakes. There isn't enough metal for strong threads and the end holes go through to the water jacket.

tom

Posted: Tue May 26, 2009 10:21 pm
by Keith Morganstein
machine shop tom wrote:I don't like the idea of drilling Vor-Tec heads for earlier style intakes. There isn't enough metal for strong threads and the end holes go through to the water jacket.

tom
Depends on what vortec.

Stock 906 / 062 gm vortecs don't have much material and you have to be careful tightening bolts.

There are some decent vortec manifolds, but adding the two center holes to vortec heads helps keep the gaskets in place.

Most aftermarket vortecs have plenty of meat for drilling.

Posted: Tue May 26, 2009 10:36 pm
by af2
They are 062.

Posted: Tue May 26, 2009 10:40 pm
by novadude
Will a standard 55-86 Performer or Performer RPM intake seal to the re-drilled vortecs, or the aftermarket heads with dual drilling (RHS, EQheads, etc), or is the Vortec port too high for a common dual plane?

Posted: Wed May 27, 2009 8:59 am
by Mike Rogers
The EQ heads you can buy with the pre 86 intake and valve cover bolt arrangement. These are not re-drills.

Posted: Wed May 27, 2009 9:27 am
by Racerrick
There is a felpro vortec gasket with both patterns. You can use it a a temp plate. Drill the head for fine thread bolts and you have no problems. Torque to 25lbs.

Posted: Wed May 27, 2009 11:25 am
by novadude
Mike Rogers wrote:The EQ heads you can buy with the pre 86 intake and valve cover bolt arrangement. These are not re-drills.
These are vortec style chambers w/ standard height intake ports?

Posted: Wed May 27, 2009 11:30 am
by robert1
I just finished an engine with 906s on it drilled for the old intake. The shop used the Goodson fixture. The holes were a little lower than I would like but ok. The end holes didn't go into water.

votec intake bolt pattern

Posted: Wed May 27, 2009 1:29 pm
by soup
We have done dozens of old intake patterns using a 1205 gasket(or 1204) as a template,just use a transfer punch.The 1255 gasket bolt pattern is not correct,the center bolt holes are too low.You have to be careful on the end bolts because they will intersect with original holes.Make sure the end bolts are sealed up when assembling.I also plug original holes with set screws,loctited.You may need to double intake gaskets.

Posted: Wed May 27, 2009 9:23 pm
by needforspeed66gt
I have that jig.

Posted: Wed May 27, 2009 9:49 pm
by af2
needforspeed66gt wrote:I have that jig.
Should I pm??
Thanks Adam

Posted: Mon Jun 01, 2009 7:17 am
by dwilliams
I made a jig from some steel flat and some drill bushings. It was a lot cheaper than buying one.

I did two pair of 062 heads. The intake faces were, oh, maybe a bit over 1/8" thick. I used 5/16" fine thread bolts to get more than two threads. Both pair of heads worked, but I always felt it was a very iffy deal. A hair too much on the wrench, and you'd be trying to figure out how to braze in a Keen-Sert or something.

Maybe not all of the heads are that thin, but I'm not happy at all with the thread engagement of the ones I did. I suggest you drill some small pilot holes first, just to see how thick your heads are, before doing this.

If I was racing in one of the stock intake/stock head classes, I'd look for one of the GM four barrel marine intakes before I'd drill another pair of Vortecs.