Exhaust crossover

I'm getting ready to pull the intake and heads off a 69 GS 400 as well as my 69 GS 350.
I'd like to block off the exhaust crossover that heats up the intake manifold. I don't really think we're going to be needing it here in Phoenix.
What have you guys used with success to block these off? Will the exhaust crossover be obvious?
Thanks,
Aubrey

 

Aubrey,
Yes they will be obvious. I blocked mine off with 2 small metal frost plugs on each head. I can't remember the exact size, but I'm sure someone else on here will know. This is where I got the info to do the same thing. It's not hard at all, just put the plugs into the holes with a small hammer.
Dan :3gears:

 

That's what I did also.

 

Hey Aubrey.I did this also during my rebuild.For you warm climate guys and really us eastern guys that don`t drive in the cold it works fine.I don`t use a choke and I find I have to feather/work the gas pedal for a few minutes untill she warms up.So far the paint has not started to lift off my B4B!! Shh..don`t tell any non Buick guys..:Brow: Hope this is what you want to hear :TU: Later,Tony.

 

I blocked the heat crossovers on my '70 heads. the plug size was 18 mm, im 99% sure hope this helps

 

18mm freeze plugs is the way to go. However, if you can find 18.05 mm plugs it will be a little better. I got mine from Advance Auto. I asked for 18mm and got the others. They only had 3 so I went down the street and got another 18mm. They definitely fit differently. The 18.05 seemed to seat better. If you can't find them the 18mm will do just fine.

 

THanks a lot giys, 18mm or better yet 18.05mm it is.
Anyone know if this will be tyhe same for the 350?

At the moment we're still soaking the cylinder head bolt with PB Breaking compound. Man those nastards are tuff. Hopefully we'll get 'em off today.

This all started on the 400 because of coolant puddling underneath both valve covers. I'm thinking it's the cylinder head gaskets. Anything else I ought to be checking while the heads are pulled. THe coolant is not turning the oil milky. Just puddling atop the cylinder heads after sitting over night.
There is probably about 4 teaspoons worth under each valve cover.

 

The early BBB heads tend to crack on top of the head under the valve covers. May want to look into that.

 

The anti freeze puddling under the valve covers is most likely form the typical cracks in th tops of almost all the 400/430 heads. The crack is between the valve springs somewhat in line with the inner 2 rocker pedestals. Jim Burek

 

Eeek, that won't be cool if that's the case.
I'll let you guys know what I find once we get these bastards off. What a pain. Been soaking 'em with PB for about 14 hours now and still nothing.

THey're so gummed up with oil and crap that it's going to difficult to see any cracks till we get them in the solvent tank for clean up.

If they are in fact cracked, what are the chances of saving the heads?
Will it depend on the size of the crack? Best just to go with some Aluminum Stae 2's? :laugh: :laugh: :laugh: :laugh:

 

Sir, are you hungry?


I dont get it o No:

 

Huh?
It's your damn car I'm working on. Just trying to get some answers.
The 350 will still kick your 400's butt all over Az.

Bring it!!!!!!!

 

Yep...

 

...looks like we're looking for a crack.

Not for crack junkie!

Whew! You're useless.

Thanks for the help y'all.