Drilling for water - 354 Industrial/Truck/Marine heads

scootermcrad · Post by **scootermcrad** » Tue Feb 13, 2007 1:19 pm

I recently picked up an Offy 6x2 intake manifold to run on my 331 with industrial heads. There are no water cross-over provisions incorporated into the manifold logs so I plan to drill and tap the heads at the front. The question is WHERE do I do this and is there anything I should know about doing this? Planning 1/2" NPT holes plumbed to a remote thermostat housing up front. Maybe someone could mark up these pictures and show me where I should be focusing. In fact, maybe someone could even just post some pics of what they have done. That would be even better...

Here's my heads, stripped and ready to go to the machine shop... (ugly huh)

scootermcrad · Post by **scootermcrad** » Wed Feb 14, 2007 7:43 am

Wow. I expected more of a response. I'm surprised. I was hoping to at least see a picture or two.

Anyone want to take a stab?

41hemi · Post by **41hemi** » Wed Feb 14, 2007 8:51 am

I have seen this done many years ago on a set of pre 55 car heads that were being used on a blown street engine that did not have water outlets in the blower intake. If I come across a picture to help see where to drill exactly I will post it here. Good Luck

budmspeeco · Post by **budmspeeco** » Fri Feb 16, 2007 9:59 pm

I have 3 sets of these heads. I will cut the end off one of them & send photos of the inside if you don't get a good answer. You will know where to drill. I have given thought to drilling them. Just no reason to do it 'till now. Buddy

wayfarer · Post by **wayfarer** » Mon Feb 19, 2007 1:48 pm

why not just pull water out of the intake rail?? most intake manifolds have enough room to sink a Â½ npt fitting into the round port.
also, keep in mind that with the ind head you have to 'shrink' the tall centre port or modify the manifold to cover it. we have had good luck putting devcon into the port to shrink it to pass car size. send a pm if you need directions.

George · Post by **George** » Mon Feb 19, 2007 4:13 pm

wayfarer wrote:why not just pull water out of the intake rail?? most intake manifolds have enough room to sink a Â½ npt fitting into the round port.
also, keep in mind that with the ind head you have to 'shrink' the tall centre port or modify the manifold to cover it. we have had good luck putting devcon into the port to shrink it to pass car size. send a pm if you need directions.

The intake he's planning on using doesn't have room for drilling.

scootermcrad · Post by **scootermcrad** » Wed Mar 07, 2007 2:41 pm

budmspeeco wrote:I have 3 sets of these heads. I will cut the end off one of them & send photos of the inside if you don't get a good answer. You will know where to drill. I have given thought to drilling them. Just no reason to do it 'till now. Buddy

Wow! That's really generous! I hope I don't need to have someone do that though! Would hate for you to ruin a set of heads on my behalf!

Besides... I may need them if I screw up!

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