C3 1968 Exhaust Manifold

[Jay L. Flinders]

Help: I have a 1968 427/390 Coup I'm restoring. I just had the engine (matching numbers to car) rebuild and placed in the car. Now I'm gathering and attaching the parts. My question is the right number for the exhaust manifolds. The NCRS pocket guide shows RH 3880828 for 66-69 427, 70 454/390 LS5, 71 454/425 LS6 w/air, and 72 454/270 w/air. The GM parts book I have shows RH 3880834 for a 66-69 427. I have a xref book that shows the same number as the Parts book. Which is the correct Number?

Second the NCRS pocket guide shows LH 3880827 for 66-69. Althought the GM parts book does not show a part number for the LH my X ref book reflects a 3880833 for 68-69 427. Which of these are correct?

Thanks Jay

[Dick W.]

Re: C3 1968 Exhaust Manifold

827 and 828 would be the correct casting #'s for '68-'69 manifolds

[John H.]

Re: C3 1968 Exhaust Manifold

PART numbers aren't always the same as CASTING numbers, and what you see in the parts book are usually PART numbers.

[Terry F.]

Re: C3 1968 Exhaust Manifold

Jay, is there any chance your engine had its original engine lift brackets attached? I am trying to collect information on them. Thanks, Terry

[Joe L.]

Re: C3 1968 Exhaust Manifold

John and Jay-----

Yes. In this case, the GM #3880827 and 3880828 are BOTH PART NUMBER and CASTING NUMBER. However, for 1968-69, they represent casting numbers ONLY.

Here's the deal: the 3880827 and 3880828 CASTING number manifolds were first used for the 1966 model year for the left and right sides, respectively, for Corvette big blocks. For 1967-69 the same manifold CASTING numbers were used.

For manifolds WITHOUT AIR fittings, the CASTING number and PART number were the same. For manifolds with AIR fittings (i.e. 66-67 with K-19 and ALL 68-69 applications) the PART numbers for these manifolds were 3880833 and 3880834, respectively, while the manifolds still carried the 3880827 and 3880828 CASTING numbers.

You will not find 3880833 or 3880834 cast on ANY manifold. You will find these numbers only on parts tags attached to NOS manifolds and/or yellow ink-stamped on NOS manifolds.