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2.7 intake runner differences

Hoping some experts can confirm what I think I know. After studying here and other sources I thought I had it figured out but then stumbled into some conflicting info.

Is the following true-

Any 74-77 2.7 engine that was an S or Carrera had the intake runners with cast ID number ending in 2R and 34.5mm ID at the outlet (head) side.

Any 74-77 2.7 base engine (74 only?) had intake runners with cast ID number ending in 0R and 31mm ID at the outlet side.

Even if these statements are true, I'd be happy to hear of any nuances or niggly details.

Thanks for any help.

bolded answers that I know, others may know more

Quote:

Originally Posted by CHUCK R (Post 12560434)

Is the following true-

Any 74-77 2.7 engine that was an S or Carrera had the intake runners with cast ID number ending in 2R and 34.5mm ID at the outlet (head) side. Yes, 2R runners are nominally 34mm to match the S head ports 35mm size

Any 74-77 2.7 base engine (74 only?) had intake runners with cast ID number ending in 0R and 31mm ID at the outlet side. 74 only base model had 32 mm head ports and 30mm 0R runners ( I have some in a box and kind of remember some measured 29mm)

Even if these statements are true, I'd be happy to hear of any nuances or niggly details.
0R runners have the WUR mount on the #2 cylinder runner backside, 2R runners have it on the front side. WUR mount sizes are slightly different.

For a good chuckle, measure the intake runners ID, they are in my experience wildly mismatched

Thanks for any help.