SBB 350 intake

[MrSony]

So, this picture has me curious: What are those blockoff plates for? especially that oval shapped bottom one? And is this a 350 intake or a 455? I do know it's buick.

 

[MrSony]

Another picture of that same intake. i found it on the web a while back and it was always confusing me. It kinda looks like a V6 intake... thoughts? How can you tell?

 

[Lue]

In case you can read the casting # on the manifold, here are a few reference #:

Year Displacement
1231381 70 350 2bbl
1231924 70 350 4bbl
1236402 71 350 2bbl
1236839 71 350 4bbl
1238578 72 350 2bbl*
1238586 72 350 4bbl
1238643 72-73 350 2bbl
1238647 72-73 350 4bbl
1242014 72-73 350 2bbl*
1242015 72-73 350 4bbl*
1245057 74 350 2bbl
1245058 74 350 4bbl
1246677 75 350 4bbl calif.
1249166 75 350 2bbl
1249168 75 350 4bbl
1382615 68 350 4bbl
1382616 68 350 2bbl
1386845 69 350 2bbl
1387069 69 350 4bbl

Heres where I got my info:

http://www.teambuick.com/reference/casting_numbers_small_block.php

 

[MrSony]

Do, I got the intake and oil pan. What is the part on the intake on both sides that kind of looks like a long tube, kinda like built in fuel rails? What are they?

 

[MrSony]

On the first pic, the smallest blockoff plate is on one of them.