KS 4 x 4 Straight Drop Exhaust - Pair - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Ironhorse** · 02-26-2025, 03:04 PM

Up for sale is a full set of the straight drop, center dump 4x4 exhaust manifolds. Manifolds have NO cracks, splits or chips. Normal cast iron surface but can be smoothed if one desires. Original GM, not cheap overseas knock-offs. Pre A.I.R. molds with no smog tube holes. Complete with the exhaust collector rings for each side and if needed, the right side cast iron carb heat collector is included. Was used as a spacer only as the center flap valve has been removed. All six exhaust studs are straight and very usable after running a thread die on each stud. $100 to your door with flat rate Priority Insured shipping, money order payment, do not have Paypal.

72Cheyenne454 · 02-26-2025, 03:43 PM

Interested in these. Can you post pictures of the top of both manifolds please.

Thanks,
Miles

**Ironhorse** · 02-26-2025, 04:05 PM

Quote:

Originally Posted by 72Cheyenne454

Interested in these. Can you post pictures of the top of both manifolds please.

Thanks,
Miles

Miles, how do you want the pic? Looking straight down with the manifolds against each other? What particular angle or straight on look are you wanting? Looking at the manifolds as they mount to the engine block? Let me know and thanks for the interest.

**Ironhorse** · 02-26-2025, 09:03 PM

Miles, not sure what you were wanting to see but here are a couple ''top'' pics of each manifold. One manifold has the hot air take off tube for the afore mentioned manifold heat for carb choke. Intact and solid, can be easily plugged if not needed or used as was intended originally. Let me know if these pics show what you wanted and thanks for your interest.

72Cheyenne454 · Yesterday, 10:37 PM

Thank you for the additional pictures, but I'm going to pass on these.

Thanks again,
Miles

**1970cstblazer** · Today, 08:36 AM

3747038 is for '64-'65 Corvette with base 327, hence the threaded boss for the hot air choke.

**Ironhorse** · Today, 11:39 AM

Wow, the rare "Corvette engine option" parts perhaps?

I had a '65 Impala SS that used that same setup with the manifold carb heat for the choke system. And YES, I was a dumb*** for selling it, who knew back then, huh? Used a slip fit metal tube from the manifold up to the side of the carb to the choke which did have the threaded connection. Looked at the manifold to be sure but the hole is not threaded....again, just a slip fit for a metal tube. Could be plugged very easily if not needing while using an 12V electric choke.

These will still work on the 4x4 engine just by plugging off the choke tube hole or can be left open. Does not interfere to the manifold as the tube passes thru to the open bottom to aid in heating the cooler air drawn in.

**Orefactory4x4 swb** · Today, 03:32 PM

Are they the 2 1/2 .?

02-26-2025, 03:04 PM	#1
Ironhorse Senior Member Join Date: Jul 2001 Location: Wellington, Ks Posts: 10,321	4 x 4 Straight Drop Exhaust - Pair Up for sale is a full set of the straight drop, center dump 4x4 exhaust manifolds. Manifolds have NO cracks, splits or chips. Normal cast iron surface but can be smoothed if one desires. Original GM, not cheap overseas knock-offs. Pre A.I.R. molds with no smog tube holes. Complete with the exhaust collector rings for each side and if needed, the right side cast iron carb heat collector is included. Was used as a spacer only as the center flap valve has been removed. All six exhaust studs are straight and very usable after running a thread die on each stud. $100 to your door with flat rate Priority Insured shipping, money order payment, do not have Paypal. Attached Images __________________ 1971 Chevy 1/2T 4x4 LWB 350 V-8 Was sm465-now 350TH/np205 Tilt, Tach, Towhooks Original Truck AM/FM Wellington, Ks

02-26-2025, 03:43 PM	#2
72Cheyenne454 Registered User Join Date: Apr 2007 Location: San Diego Posts: 459	Re: 4 x 4 Straight Drop Exhaust - Pair Interested in these. Can you post pictures of the top of both manifolds please. Thanks, Miles

02-26-2025, 09:03 PM	#4
Ironhorse Senior Member Join Date: Jul 2001 Location: Wellington, Ks Posts: 10,321	Re: 4 x 4 Straight Drop Exhaust - Pair Miles, not sure what you were wanting to see but here are a couple ''top'' pics of each manifold. One manifold has the hot air take off tube for the afore mentioned manifold heat for carb choke. Intact and solid, can be easily plugged if not needed or used as was intended originally. Let me know if these pics show what you wanted and thanks for your interest. Attached Images __________________ 1971 Chevy 1/2T 4x4 LWB 350 V-8 Was sm465-now 350TH/np205 Tilt, Tach, Towhooks Original Truck AM/FM Wellington, Ks

Yesterday, 10:37 PM	#5
72Cheyenne454 Registered User Join Date: Apr 2007 Location: San Diego Posts: 459	Re: 4 x 4 Straight Drop Exhaust - Pair Thank you for the additional pictures, but I'm going to pass on these. Thanks again, Miles

Today, 08:36 AM	#6
1970cstblazer All stock and staying that way Join Date: Jul 2003 Location: Elkland, PA Posts: 2,028	Re: 4 x 4 Straight Drop Exhaust - Pair 3747038 is for '64-'65 Corvette with base 327, hence the threaded boss for the hot air choke. __________________ 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, 11:39 AM	#7
Ironhorse Senior Member Join Date: Jul 2001 Location: Wellington, Ks Posts: 10,321	Re: 4 x 4 Straight Drop Exhaust - Pair Wow, the rare "Corvette engine option" parts perhaps? I had a '65 Impala SS that used that same setup with the manifold carb heat for the choke system. And YES, I was a dumb*** for selling it, who knew back then, huh? Used a slip fit metal tube from the manifold up to the side of the carb to the choke which did have the threaded connection. Looked at the manifold to be sure but the hole is not threaded....again, just a slip fit for a metal tube. Could be plugged very easily if not needing while using an 12V electric choke. These will still work on the 4x4 engine just by plugging off the choke tube hole or can be left open. Does not interfere to the manifold as the tube passes thru to the open bottom to aid in heating the cooler air drawn in. __________________ 1971 Chevy 1/2T 4x4 LWB 350 V-8 Was sm465-now 350TH/np205 Tilt, Tach, Towhooks Original Truck AM/FM Wellington, Ks

Today, 03:32 PM	#8
Orefactory4x4 swb Senior Member Join Date: Mar 2023 Location: Springfield oregon Posts: 208	Re: 4 x 4 Straight Drop Exhaust - Pair Are they the 2 1/2 .?

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