440-6 cast iron intake 2946275 issues

[mtull]

I have a 440-6 cast iron intake with casting number 2946275 dated June 17, 1969.  Supposedly the intakes were discontinued due casting issues allowing exhaust gasses to enter the intake from the exhaust crossover.  Does anyone have or know of any service bulletins discussing the issue?  If this intake had the aforementioned problem, what would the symptoms be?  Would a pressure test reveal anything?

Thank you
M.

[Cuda Cody]

I would think a pressure test would tell, right?  Does anyone else have any info on this?

[Mr Cuda]

 I never heard of any recall or problem with the cast iron, other than being heavy.
 I guess I should go look at mine.

[mtull]

I would think a pressure test would tell, right?  Does anyone else have any info on this?

Thank you.  I was thinking/hoping the same.

[larry4406]

This link talks to the 2946275 casting has having porosity issues (third post)
https://board.moparts.org/ubbthreads/ubbthreads.php/topics/1696762/all/440-6-pack-iron-intake-manifold-dates-details-please.html

[mtull]

I never heard of any recall or problem with the cast iron

Supposedly, early cars had the 275 intake.  The previously mentioned casting issues were found so the factory went back to aluminum while a new intake was cast (2946276).  I recall one post stating they've never had an issue with their 275 intake, so it must have been hit or miss problem. 

I found most of the info in old posts over on board.moparts.org and the E-Bodies.org Facebook group but didn't save the links.  I was originally wondering if the aluminum six pack intakes were painted or left natural on 1970 model year cars.  One post suggested their all original 1970 Road Runner, never apart, never restored had a painted aluminum intake. 

[mtull]

This link talks to the 2946275 casting has having porosity issues (third post)
https://board.moparts.org/ubbthreads/ubbthreads.php/topics/1696762/all/440-6-pack-iron-intake-manifold-dates-details-please.html

Thank you ... that was one of the threads I was referring to in my last post but couldn't find it a few moments ago.

[Mr Cuda]

 Well, I hope the problem was with earlier ones.
 Mine is a 275 casting with a 7/11 date.
 It came with the car, 12/69 production from LA. No original motor, so can't confirm anything.
 Steel shim the exhaust crossover shut? I wasn't going to rely on choke anyway. I guess I'll have to pressure test to see if it even leaks.
 I was going to run an aluminum, just because.

[6bblgt]

I never heard of anyone having an issue with a used 2946275 intake - there would be thousands of them
maybe the issue was with the actual molds at the plant, not the parts produced   

[mtull]

there would be thousands of them

fingers crossed @Mr Cuda and I aren't the first ones you hear about.