I have an old 340 intake manifold, but the casting numbers don't match anything I can find. Instead of something like 3462848, I have 100340 3. There is no pentastar cast in, but the firing order and distributor rotation are both cast in. Can anyone help me identify this intake. I'll take some photos if that will help.

 

post up a couple photos.... That may help...

 

I can't read what this says.

 

Looks like it says 10/5/1976 for the year?
Not really a performance Intake Manifold.... Has EGR and a Heat Riser Crossover...
It's for sure a Small Block intake...
I Could not find any Casting number to cross reference ....

 

I think you are correct on the date, thanks for the information.