Help Decoding Exhaust Manifolds. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Getter-Done** · 02-25-2025, 10:29 PM

If I remember correctly,
Someone on the forum has a Book that covers the Castings numbers on Intake and Exhaust manifolds.

I used my Normal searches and some of Same Cast # manifolds that I found on E bay

looks different.
I think it has something to do with the LH 24 & RH 6 under the casting #.

So Here is my Question.

Does anyone know what this Pair of Exhaust Manifolds came off of?

Left manifold has a casting # of 3832473 with LH 24 under it.
Edit for Future Reference this casting number is 3932473.
Thanks 1970cstblazer for the info.

Right Manifold has a casting # of 3838956 with a RH 6 under it.

Thanks in advance for the help.

My guess is a 69/70 307cid.?

Name: lh.jpg
Views: 141
Size: 24.3 KB

**1970cstblazer** · 02-26-2025, 02:02 PM

Top one is 3932473 which is a LH 1969-70 2WD. The LH 24 refers to the side and which mold it was cast in. K series 4WD trucks use a RH straight dump manifold 3932465 on both sides.

3838956 does not exist. However, 3896956 is a '67-'70 RH manifold for 2WD 307, 327, 350 W/O A.I.R.

**Getter-Done** · 02-26-2025, 03:42 PM

So the second number is a 9.

That makes sense.

Thank You so much.

**MJN** · 02-26-2025, 06:55 PM

Just adding what my book says:
3932473: Left hand, 307/350, 69-70 Passenger car, W/O A.I.R., angled dump, no bracket

3896956: Right hand, 283/307/327, 67-68 Truck, W/O A.I.R., angled dump, no bracket

**Getter-Done** · 02-27-2025, 12:39 AM

Quote:

Originally Posted by MJN

Just adding what my book says:
3932473: Left hand, 307/350, 69-70 Passenger car, W/O A.I.R., angled dump, no bracket

3896956: Right hand, 283/307/327, 67-68 Truck, W/O A.I.R., angled dump, no bracket

Thanks

I Appreciate the info.

z10kl · Yesterday, 08:19 PM

Quote:

Originally Posted by 1970cstblazer

Top one is 3932473 which is a LH 1969-70 2WD. The LH 24 refers to the side and which mold it was cast in. K series 4WD trucks use a RH straight dump manifold 3932465 on both sides.

3838956 does not exist. However, 3896956 is a '67-'70 RH manifold for 2WD 307, 327, 350 W/O A.I.R.

Is the 465 correct for a 71 K20 too?

**1970cstblazer** · Yesterday, 08:36 PM

336711 is correct for all K series 1971 trucks and Blazers.

z10kl · Today, 11:13 AM

Quote:

Originally Posted by 1970cstblazer

336711 is correct for all K series 1971 trucks and Blazers.

Thank you for the info

**71CHEVYSHORTBED402** · Today, 01:43 PM

Link to page:
http://www.gmpartswiki.com/getpage?pageid=21508

02-25-2025, 10:29 PM	#1
Getter-Done Senior Member Join Date: Dec 2009 Location: TN. Posts: 8,627	Help Decoding Exhaust Manifolds. If I remember correctly, Someone on the forum has a Book that covers the Castings numbers on Intake and Exhaust manifolds. I used my Normal searches and some of Same Cast # manifolds that I found on E bay looks different. I think it has something to do with the LH 24 & RH 6 under the casting #. So Here is my Question. Does anyone know what this Pair of Exhaust Manifolds came off of? Left manifold has a casting # of 3832473 with LH 24 under it. Edit for Future Reference this casting number is 3932473. Thanks 1970cstblazer for the info. Right Manifold has a casting # of 3838956 with a RH 6 under it. Thanks in advance for the help. My guess is a 69/70 307cid.? __________________ ________________________________________________________________________________________ ____________________________________________ The early bird gets the worm, But the second mouse gets the cheese 84 Chevy K-20 63 Impala (my high school car) http://67-72chevytrucks.com/vboard/s...Crew Cab Build Last edited by Getter-Done; 02-27-2025 at 12:31 AM.

02-26-2025, 02:02 PM	#2
1970cstblazer All stock and staying that way Join Date: Jul 2003 Location: Elkland, PA Posts: 2,041	Re: Help Decoding Exhaust Manifolds. Top one is 3932473 which is a LH 1969-70 2WD. The LH 24 refers to the side and which mold it was cast in. K series 4WD trucks use a RH straight dump manifold 3932465 on both sides. 3838956 does not exist. However, 3896956 is a '67-'70 RH manifold for 2WD 307, 327, 350 W/O A.I.R. __________________ 1970 K/5 Blazer CST 4WD, TOTM winner December 2024! Medium Bronze poly, 93k ACT. miles, 350, 4 speed, rear positraction, 16.5" x 8.25" HD Kelsey Hayes wheel option, tilt, tach, vacuum, AM/FM, manual throttle...Dad ordered and purchased new 4/70. Currently frame off restoration finally getting close to completion.. 1970 K20, To be a clone of my Grandfather's K20, Dark Blue poly, 350, 4 speed, 16.5" X 8.25" Kelsey Hayes wheel option, tilt, tach, vacuum, AM radio. Latest project truck 1972 Cheyenne Super 20 2WD, Dark Blue/White, 90K ACT. miles, 402, TH400, 4.10 open, tilt, tach, vacuum, A/C, AM/FM, manual throttle.. A mostly original paint never rusted Texas survivor... 2017 Sierra 1500 SLT 4WD, Black, 46k miles, 5.3, 6L80E, 3.42 LS, 20" polished wheels, everything but moonroof and 6.2... 2019 Canyon SLT 4WD, White, 67k miles, 3.6, 8L45, 3.23 LS, 18" wheels Last edited by 1970cstblazer; 02-26-2025 at 02:12 PM.

02-26-2025, 03:42 PM	#3
Getter-Done Senior Member Join Date: Dec 2009 Location: TN. Posts: 8,627	Re: Help Decoding Exhaust Manifolds. So the second number is a 9. That makes sense. Thank You so much. __________________ ________________________________________________________________________________________ ____________________________________________ The early bird gets the worm, But the second mouse gets the cheese 84 Chevy K-20 63 Impala (my high school car) http://67-72chevytrucks.com/vboard/s...Crew Cab Build

02-26-2025, 06:55 PM	#4
MJN Registered User Join Date: Feb 2000 Location: Maquoketa, Ia/ Orr, Mn Posts: 3,086	Re: Help Decoding Exhaust Manifolds. Just adding what my book says: 3932473: Left hand, 307/350, 69-70 Passenger car, W/O A.I.R., angled dump, no bracket 3896956: Right hand, 283/307/327, 67-68 Truck, W/O A.I.R., angled dump, no bracket __________________ '51 South Bend Model "9A" '56 Chevy 3600 NAPCO '74 Chevy Cheyenne Super K20-restored on 37's '72 GMC Sierra Custom K2500- in progress '08 GMC Envoy Denali '12 GMC Sierra 2500HD Denali '17 GMC Yukon XL VCCA member #58596 http://www.nohrco.com

Yesterday, 08:36 PM	#7
1970cstblazer All stock and staying that way Join Date: Jul 2003 Location: Elkland, PA Posts: 2,041	Re: Help Decoding Exhaust Manifolds. 336711 is correct for all K series 1971 trucks and Blazers. __________________ 1970 K/5 Blazer CST 4WD, TOTM winner December 2024! Medium Bronze poly, 93k ACT. miles, 350, 4 speed, rear positraction, 16.5" x 8.25" HD Kelsey Hayes wheel option, tilt, tach, vacuum, AM/FM, manual throttle...Dad ordered and purchased new 4/70. Currently frame off restoration finally getting close to completion.. 1970 K20, To be a clone of my Grandfather's K20, Dark Blue poly, 350, 4 speed, 16.5" X 8.25" Kelsey Hayes wheel option, tilt, tach, vacuum, AM radio. Latest project truck 1972 Cheyenne Super 20 2WD, Dark Blue/White, 90K ACT. miles, 402, TH400, 4.10 open, tilt, tach, vacuum, A/C, AM/FM, manual throttle.. A mostly original paint never rusted Texas survivor... 2017 Sierra 1500 SLT 4WD, Black, 46k miles, 5.3, 6L80E, 3.42 LS, 20" polished wheels, everything but moonroof and 6.2... 2019 Canyon SLT 4WD, White, 67k miles, 3.6, 8L45, 3.23 LS, 18" wheels

Today, 01:43 PM	#9
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,381	Re: Help Decoding Exhaust Manifolds. Link to page: http://www.gmpartswiki.com/getpage?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



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.