Hey all, I've been off the forum for a while but finally back working on the Olds.

My intake manifold cracked around the choke heater bolt housing when I was trying to remove a broken bold from the housing. I am looking into having it repaired, but would like to replace it. Some day I may switch over to a 4bbl, but I just had the 2bbl rebuilt and don't want to spend the money to go to a 4bbl setup. Just a cruising car and the 2bbl works great around town.

My recollection is that 73 is the first year for EGR engines, so the manifolds are different from 73+. What years are interchangeable and what years are different? Car has been running fine with the stock configuration so I'm happy to keep it like that.

Any advice on getting the crack repaired? I assume welding is off the table for a cast manifold, so its JB Weld, brazing or maybe silver soldering? I have a good weld shop I know who has experience with cast iron, but of course they're expensive. Not my first choice, but something Id consider.

As far as replacing it:
What years of 350 intakes will bolt on? Is it better to just go by casting number?
Any good places to look or users to message? Ive already posted in the classifieds section.
As far as buying a used manifold, anything to look for? Is a visual inspection enough to check for cracks or can/should they be pressure tested?
How bad can the gasket surfaces be before they have to be faced?

Of course, if you have one you're willing to part with, PM me!

Thanks,
PTTM

 

You should not have any problems finding one. Pretty common part.

 

Also, any advice on where/how to replace the choke tubes? I have the loop that bolts into the manifold, but the tube that runs up to the intake and the tube that runs to the choke coil are both rusting apart.

 

All are available @ InLineTube

 

Ooops... I may have mis-spoken. InLineTube parts are 1964-1972. I believe you have a 1973? Or, is your 455 an earlier year? Page 195 of the Oldsmobile InLineTube catalog.

 

Well the car is a 73 and the engine is a 350, but it seems that the manifold casting number does not match a 350 from 73, so until I get the exact manifold nailed down, I imagine correct choke tubes will be hard to determine.



Manifold casting and the factory tubes next to some new ones I bought which don't match. Think they were a 72 350 2bbl

 

Many years ago before the internet was invented I made upper choke tubes out of copper tubing.

 

Im thinking about making my own. Did you make it with one piece of tube or with 3 like the factory setup?

 

I made just the upper two piees, not the U shaped heater that goes into the intake manifold.

 

OK, so what I can't figure out is how to compress/neck down the end of the tube to slide into the heater loop in the manifold.

The flare for the nut that holds it onto the choke spring, I can do, but that end that goes into the heater is rolled or pressed to a smaller diameter.

Did you just find a size of copper tube that fit into the choke heater, or what tool do I need to make that fit work?

 

This was back in the 1980s (about 35 years ago) so I don't remember exactly what I did, but I seem to recall that I had to taper the end of the tube. Maybe I used a file to thin the OD of the tubing? Anyway, I somehow got it to a slightly smaller diameter and just jammed it into the U tube for a friction fit. Once the other ends were secured, the new tubes stayed in place.