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Does anyone have a GM Iron intake manifold laying around loose they could measure?
Off of an L36 or an LS5.
I have a pretty good intake manifold height chart, but no one seems to have a measurement of a stock manifolds.
Likely somewhere around 3.0 to 3.8"
Both front and rear measurements, to the top of the china wall.
I just happen to have my '67 L-36 on a stand with no carb. This is measured, as best I could, to the bottom of the intake and not the top of the block.
Front looks like 4 &1/16".
Rear looks like 5 & 1/2" (maybe just a fraction over).
Thanks Owen!
Do you have casting number? 3883948?
QJet type?
Wow that is much taller than I thought.
But is a '67 C2 intake.
Here is what I have so far:
Most numbers are from mfgr liter.
I have front & rear measurements for all bu the top four.
I still need to confirm the first three.
The BIGGEST issue I found so far is ALL the sellers have the same "height" for the LS6 manifold, and it is WRONG!
I just measured one.
Last edited by leigh1322; Jul 18, 2025 at 08:17 PM.
So it looks like the C2 BB intake is a high rise and is 1-1/2" taller than a 68-72 BB low-rise intake.
I knew they were taller, I always wondered how much.
Now I know how an L88 intake can fit under that same scoop, it is only 1/4" taller.
Now I would love to get a measurement on a 68-69 aluminum QJet L36 intake. 3947801
I read it is 3.5" but would like to have someone measure one to confirm.
That would make it 1/2" taller than a LS5 or LS6 intake.
So it looks like the C2 BB intake is a high rise and is 1-1/2" taller than a 68-72 BB low-rise intake.
I knew they were taller, I always wondered how much.
Now I know how an L88 intake can fit under that same scoop, it is only 1/4" taller.
Now I would love to get a measurement on a 68-69 aluminum QJet L36 intake. 3947801
I read it is 3.5" but would like to have someone measure one to confirm.
That would make it 1/2" taller than a LS5 or LS6 intake.
I had no idea and am really surprised there is that much height difference between them all! I guess the new body really cut down on ceiling height.
I also didn't know that the L-36 QJet was aluminum... that would save a bit of weight.
I found a pic of a two GM BBC intakes.
One low rise and one high rise.
It's a pretty dramatic difference.
The one is a black marine intake, but it looks as high as an L88 or L78, the other looks as flat as the 454s stockers that I remember.
My notes say one should be 5.0" high and the other 3.0". Looks about right. It's a 2.0" difference.
Looks like your C2 intake is only about 1/4" shorter than the left one.
Last edited by leigh1322; Jul 19, 2025 at 10:28 PM.
BBC Intake Manifold height measurement needed
