I am restoring a 1970 d100 truck with a slant six and I am most of the way through refreshing the engine which is coming along nicely.
Today I pulled out the intake and exhaust manifolds and scraped all of the soot and greasy mess off of them, and ran them through the parts washer.
Interestingly the intake manifold shows signs of lots of turquoise engine paint on it from the factory (this truck has been in the family since new and has never been touched).
I was thinking of sand blasting the manifolds to make them look nicer, but I am wondering what you guys suggest to "freshen" them up for reassembly onto my freshly painted engine.
I could leave them bare which would let them start to look crappy right away again (which is what they did when new I suppose) or I know there are some special manifold paints out there from Eastwood that keep the mainfolds looking newly cast.
Any suggestions or tips?
Of course I have to go back out to the shop and drill and tap out some snapped off bolts as per usual!

The '70-'72 exhaust manifolds have a problem-prone choke pocket setup: a stainless steel cup in an open hole at the top of the tower on the № 5 runner. The gasket for this cup is no longer available, and that junction tends to leak. Moreover, exhaust manifolds of whatever year tend to warp and develop other problems over the years. In the long run it will pay you (bigtime) to buy this and install it. It's the heavy-duty nodular iron (warp/crack-resistant) manifold, and it doesn't have that problematic gasket/cup style choke attachment. You'll want an Electric choke kit if your truck's carburetor has automatic choke.

Nothing wrong with sandblasting the intake to get it super-clean before painting it (as long as you make very sure to get all the sand gone before reinstall!) but you can also hot-tank it, or use oven cleaner.

Turquoise on some '69 225, yellow on others in trucks. Chrysler Blue on '70-up engines. Sometimes it fades to a lighter turquoise-y shade with age. Pick what colour you want on your engine in your truck.

It is very much worth your while to get the good gaskets for the manifolds-to-head and intake-to-exhaust junctions.

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Too many people who were born on third base actually believe they've hit a triple.

Thanks for the suggestions.
I never realized the intakes were painted; my engine is factory turquoise so it will go back to that for sure.
I did notice the gasket was crumbling in the choke well you are referring to. I am on a tight budget and a new exhaust manifold is not going to happen; how can I go about sealing that up? Is it possible to make your own gasket for that choke well?
I have ordered the high end exhaust gasket set as recommended here on the forum.
My carb is a factory single barrel manual choke set up.

a couple of more questions regarding the manifolds; the 3 long bolts that hold the 2 manifolds together snapped on disassembly.
IObviously the front single bolt is threaded into the exhaust manifold, but the 2 outside bolts go through the exhaust manifold and had nuts on the bottom side. Are the holes in the exhaust manifold threaded or are they smooth and the nuts do all the tightening on the other side? Want to be sure before I start drilling out if I need to tap or not.
Also, what are the diameters and lengths of the 3 bolts? They will obviously need replacing.
I'm surprised they would tap threads into a cast manifold for the front single bolt of the three!

All the holes in the exhaust manifold used to join it to the intake manifold were originally threaded. The inner hole originally had a stud as did the exhaust pipe flange.

Have you read the manifold installation article? http://www.slantsix.org/articles/manifo ... unting.htm

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Joshua

thanks for the link; is it best to put a stud back into that lone hole on the exhaust manifold? If so does anyone have any idea how long it is, or is there an exhaust bolt set for attaching the 2 manifolds together you can buy?

Good news; the snapped off manifold join bolts are fairly soft and drilled out and tapped pretty easily.

Can anyone suggest how I can go about re sealing up the choke pocket being that the gasket is not available to buy anymore?
I’ve got both of my manifolds cleaned and painted, ready to reassemble.

Anyone?

I wish I could help, but I haven't used stock int and exh together in about 20 yrs... I have a stack of the steel gaskets about 1" thick, though, if you need any of those...

Lou

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Home of Slant6-powered fun machines

Part № 2946 530, looks like there are five in stock at www.arizonaparts.com for $6 apiece.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks!