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**71CHEVYSHORTBED402** · 04-26-2015, 12:54 AM

Seeking an education please. EDIT: EDUCATED. The variable is for A.I.R., not air conditioning.

I was looking into fitting the heat shield for the stove pipe for the 402. Out of curiosity, I took note of the exhaust manifolds, which are (LH 3994045) and (RH 353030). First off, the truck is stock A/C. I just never put it back on with a engine rebuild long ago, but I plan on re-assembling. So here's where the fun begins. Take a peak at this here Wiki link, right out of the Light Truck Parts Catalog (below).

First, I don't believe they put a 396 in a 1971 Chevy (402 replaced the 396). Second, they don't show a 402 (aka 400) for the 1971, but they do for a 1972............They also don't differentiate between exhaust manifolds (A/C and not) within the grid for 1971.

If that wasn't confusing enough, if I go by the 1971 396, then my LH exhaust manifold is correct (assuming A/C doesn't matter), but the RH manifold is incorrect. If I go by the 1972 400, then the LH exhaust manifold is incorrect for A/C, but the RH is correct for A/C.

WTH? With all this mess in mind, safe to say the A/C cannot be mounted properly with one of these exhaust manifolds?

For the record, the heads on this 402 came off of a 396. I'm way to green to know if that matters for this application, though I suspect it doesn't. The LH exhaust manifold had to be replaced with the engine rebuild.

HELP!

http://www.t.gmpartswiki.com/getbigpage?pageid=21508

04-26-2015, 12:54 AM	#1
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,391	1971 Big Block Exhaust Manifolds??????? Seeking an education please. EDIT: EDUCATED. The variable is for A.I.R., not air conditioning. I was looking into fitting the heat shield for the stove pipe for the 402. Out of curiosity, I took note of the exhaust manifolds, which are (LH 3994045) and (RH 353030). First off, the truck is stock A/C. I just never put it back on with a engine rebuild long ago, but I plan on re-assembling. So here's where the fun begins. Take a peak at this here Wiki link, right out of the Light Truck Parts Catalog (below). First, I don't believe they put a 396 in a 1971 Chevy (402 replaced the 396). Second, they don't show a 402 (aka 400) for the 1971, but they do for a 1972............They also don't differentiate between exhaust manifolds (A/C and not) within the grid for 1971. If that wasn't confusing enough, if I go by the 1971 396, then my LH exhaust manifold is correct (assuming A/C doesn't matter), but the RH manifold is incorrect. If I go by the 1972 400, then the LH exhaust manifold is incorrect for A/C, but the RH is correct for A/C. WTH? With all this mess in mind, safe to say the A/C cannot be mounted properly with one of these exhaust manifolds? For the record, the heads on this 402 came off of a 396. I'm way to green to know if that matters for this application, though I suspect it doesn't. The LH exhaust manifold had to be replaced with the engine rebuild. HELP! http://www.t.gmpartswiki.com/getbigpage?pageid=21508 __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assembly guide (kit) for restoring this truck from the ground up, complete with details including full hardware descriptions. Much of the info. applies to all 67-72 GM. My build thread, with some info. about the assembly kit https://67-72chevytrucks.com/vboard/...d.php?t=730025 Last edited by 71CHEVYSHORTBED402; 04-26-2015 at 09:03 PM.