Is this a Front Exhaust Pipe p/n error in the 1967 AIM, for 300hp base engine + M35?

[Scott S.]

Is this a 1967 AIM error, or am I misunderstanding the SB front exhaust pipes for a Corvette with Manual Trans. vs. Powerglide?

Background: the 1966 AIM, UPC 8-A2 (standard Exhaust System), shows front exhaust pipe p/n 3849867 & 3849868. This would be the front exhaust pipe part number for a 300hp base engine with manual (3-spd) transmission. It would remain the same p/n with a 4-spd. This should be a front exhaust pipe that is 2.5" OD, except swaged down to 2.0" where it attaches to the exhaust manifold. If a 300hp base engine was equipped with M35, it used a front exhaust pipe that was 2.0" OD the full length, called out on M35-A1, GM 3849865 & GM 3849866, confirmed by the P&A as being for 327 w/P.G.

Now the 1967 AIM. On UPC 8-A2 (standard Exhaust System) there is a new p/n for the front exhaust pipes, GM 3877209 & 3877210, and the Revision Record shows an AIM date change of 1-9-67, showing that it had been the 1966 part numbers (3849867, 3849868), which again were front exhaust pipes with a 2.5" OD swaged down to 2.0" at the exhaust manifold. Whatever required the change in p/n, the new (as of approx. 1-9-67) front exhaust pipes should still have been 2.5" OD necked down to 2.0" at the exh. mfld.

The suspected error is that the front exhaust pipe part numbers called out in the 1967 AIM for the 300hp base engine with M35 (UPC M35-A1) are GM 3849867 & 3849868, which were the STANDARD 2.5" OD Front Exhaust Pipe part numbers for 1966 and the first half of 1967 production for small block Corvettes with Manual Transmission.


Is it correct that the part numbers called out for the front exhaust pipes in the '67 AIM on UPC M35-A1 for a 300hp base engine with M35 are in error, and SHOULD be the same 2.0" OD pipes (GM 3849865 & 3849866) called out in the 1966 AIM, UPC M35-A1?

Or what am I missing?

[Joe L.]

Re: Is this a Front Exhaust Pipe p/n error in the 1967 AIM, for 300hp base engine + M

Is this a 1967 AIM error, or am I misunderstanding the SB front exhaust pipes for a Corvette with Manual Trans. vs. Powerglide?

Background: the 1966 AIM, UPC 8-A2 (standard Exhaust System), shows front exhaust pipe p/n 3849867 & 3849868. This would be the front exhaust pipe part number for a 300hp base engine with manual (3-spd) transmission. It would remain the same p/n with a 4-spd. This should be a front exhaust pipe that is 2.5" OD, except swaged down to 2.0" where it attaches to the exhaust manifold. If a 300hp base engine was equipped with M35, it used a front exhaust pipe that was 2.0" OD the full length, called out on M35-A1, GM 3849865 & GM 3849866, confirmed by the P&A as being for 327 w/P.G.

Now the 1967 AIM. On UPC 8-A2 (standard Exhaust System) there is a new p/n for the front exhaust pipes, GM 3877209 & 3877210, and the Revision Record shows an AIM date change of 1-9-67, showing that it had been the 1966 part numbers (3849867, 3849868), which again were front exhaust pipes with a 2.5" OD swaged down to 2.0" at the exhaust manifold. Whatever required the change in p/n, the new (as of approx. 1-9-67) front exhaust pipes should still have been 2.5" OD necked down to 2.0" at the exh. mfld.

The suspected error is that the front exhaust pipe part numbers called out in the 1967 AIM for the 300hp base engine with M35 (UPC M35-A1) are GM 3849867 & 3849868, which were the STANDARD 2.5" OD Front Exhaust Pipe part numbers for 1966 and the first half of 1967 production for small block Corvettes with Manual Transmission.


Is it correct that the part numbers called out for the front exhaust pipes in the '67 AIM on UPC M35-A1 for a 300hp base engine with M35 are in error, and SHOULD be the same 2.0" OD pipes (GM 3849865 & 3849866) called out in the 1966 AIM, UPC M35-A1?

Or what am I missing?

Scott-----


Yes, it's an error if that's what it says. The GM #3849865 and 3849866 are the front exhaust pipes for 1967 Corvettes with 300 HP and M35.

[David L.]

Re: Is this a Front Exhaust Pipe p/n error in the 1967 AIM, for 300hp base engine + M

Scott,

My 1967 Chev. Parts Catalogs (Feb. & July 1967) list the following in Gr. 3.609:
66-67 w/P.G. (327), GM # 3849865 (LH front) and GM # 3849866 (RH front)
66-67 (327)(exc. P.G.), GM # 3877209 (LH) and 3877210 (RH)

Dave

[Scott S.]

Re: Is this a Front Exhaust Pipe p/n error in the 1967 AIM, for 300hp base engine + M

Scott-----


Yes, it's an error if that's what it says. The GM #3849865 and 3849866 are the front exhaust pipes for 1967 Corvettes with 300 HP and M35.

Thanks Joe.

The only other explanation I could think of was that maybe they "upgraded" to the 2.5" OD exhaust pipes for 300hp w/M35, or possibly, allowed M35 with L79 and standard Manual Transmission front exhaust pipes. But even then, looking at the different shapes of the 2.5" Man. Trans. front exhaust pipes vs. the 2.0" M35 front exhaust pipes, it doesn't look like the standard Man. Trans. front exhaust pipes are configured to allow them to be installed with the Powerglide transmission, in which case the standard SB front exhaust pipes with M35 would not even be possible.

[Scott S.]

Re: Is this a Front Exhaust Pipe p/n error in the 1967 AIM, for 300hp base engine + M

Scott,

My 1967 Chev. Parts Catalogs (Feb. & July 1967) list the following in Gr. 3.609:
66-67 w/P.G. (327), GM # 3849865 (LH front) and GM # 3849866 (RH front)
66-67 (327)(exc. P.G.), GM # 3877209 (LH) and 3877210 (RH)

Dave

Thanks Dave, I found the part numbers you reference. The M35-A1 page in the '67 AIM is in error, calling out front exhaust pipes GM 3849867, 3849868 which are the 2.5" pipes, equivalent to the GM 3877209, 3877210 pipes which as you show, exclude Powerglide.