N14 NOS Pipes

[George T.]

I have a NOS pair of 3872971 and 72 N14 side pipes. Unfortunately they don't fit my big block '66. AIM shows 3872969-70 for my L36 and 3877215-6 for the L79. Anyone know what the 71/72's fit? Need to make a trade.

[Joe L.]

Re: N14 NOS Pipes

I have a NOS pair of 3872971 and 72 N14 side pipes. Unfortunately they don't fit my big block '66. AIM shows 3872969-70 for my L36 and 3877215-6 for the L79. Anyone know what the 71/72's fit? Need to make a trade.

George-----


The 3872971 and 3872972 are applicable to 1965 Corvette with 327 and side-mounted exhaust.

[Mike M.]

Re: N14 NOS Pipes

Interesting, what's the difference between the two SB pipes?
HaND

[Robert G.]

Re: N14 NOS Pipes

I think the difference is 2" vs 2 1/2" exhaust manifolds.

[Mike M.]

Re: N14 NOS Pipes

Even more interesting.
Research, archives of previous posts and the '65 JG, all agree that 2" side pipes were not available in '65 production, or, even later production as the '66 & '67 base 300 engines used 2-1/2" Exhaust Manifolds.
If these 2971-2 are in fact 2". Were did they come from?
Were they made available much later by GM, after '65 production as "Over the Counter" Service Replacement, Revenue Enhancement Opportunity?
Contrary to the above production availability, we have seen N14's added to 250 HP and PG cars. I just figured they were supplied by the after market.
WADDUP?
HaND

[Joe L.]

Re: N14 NOS Pipes

Even more interesting.
Research, archives of previous posts and the '65 JG, all agree that 2" side pipes were not available in '65 production, or, even later production as the '66 & '67 base 300 engines used 2-1/2" Exhaust Manifolds.
If these 2971-2 are in fact 2". Were did they come from?
Were they made available much later by GM, after '65 production as "Over the Counter" Service Replacement, Revenue Enhancement Opportunity?
Contrary to the above production availability, we have seen N14's added to 250 HP and PG cars. I just figured they were supplied by the after market.
WADDUP?
HaND

Mike------


The only 66-67 Corvette engines that used 2-1/2" outlet manifolds were big blocks. All 1966-67 small blocks used 2" outlet manifolds. Some did have 2-1/2" exhaust but it was 2" at the manifold.

After 1965, no C2 or C3 Corvette small block ever used a 2-1/2" outlet manifold.

[George T.]

Re: N14 NOS Pipes

The 71/72 are 2 1/2" and GM. Still has the GM stickers showing the part numbers. They turn up at 90 degress at the manifold so looks like SB and definately not BB. I've had them about 20 years but not sure how old they are. Likely were replacement parts and not made in '65 or '66.

George

[Joe L.]

Re: N14 NOS Pipes

The 71/72 are 2 1/2" and GM. Still has the GM stickers showing the part numbers. They turn up at 90 degress at the manifold so looks like SB and definately not BB. I've had them about 20 years but not sure how old they are. Likely were replacement parts and not made in '65 or '66.

George

George------

If you're referring to the forward exhaust PIPES, then, yes, SOME 1971-72 small blocks were 2-1/2". For these years, the only ones that used 2-1/2", though, were LT-1's.

If you're talking about exhaust manifolds (which is what I was talking about), then NO small block after 1965 used 2-1/2" outlet manifolds, not 1971, 1972 or any other year.

[George T.]

Re: N14 NOS Pipes

George------

If you're referring to the forward exhaust PIPES, then, yes, SOME 1971-72 small blocks were 2-1/2". For these years, the only ones that used 2-1/2", though, were LT-1's.

If you're talking about exhaust manifolds (which is what I was talking about), then NO small block after 1965 used 2-1/2" outlet manifolds, not 1971, 1972 or any other year.

Thanks for the reply, Joe. I was refering to the connection between the side pipe and the manifold. The pipe is 2 1/2" from the manifold to the "tuned" section with no size transitions. Part number on the side pipes is 3872971 (left) and 3872972 (right).

[Joe L.]

Re: N14 NOS Pipes

Thanks for the reply, Joe. I was refering to the connection between the side pipe and the manifold. The pipe is 2 1/2" from the manifold to the "tuned" section with no size transitions. Part number on the side pipes is 3872971 (left) and 3872972 (right).

George------


OK, I thought you were referring to year models with the 71/72 and not part numbers. If the 3872971 and 3872972 have 2-1/2" inlets, then they could only have been used with 1965 small blocks that were also equipped with 2-1/2" outlet manifolds. Since these are the only part numbers I show for 1965 small block with side exhaust, I guess that base engine or 300 hp with Powerglide could not have been ordered with the N14 option.