Smog?

[61 vert]

Is a late COPO Chevelle a smog car?(manifolds, pump,diverter valve etc.)

[Mr70]

Yep!

[Keith Tedford]

Ours was one of the last ones built in Baltimore and it had full smog. Sure made for disappointing performance. Once the headers were added, timing and jetting sorted out, it was a different car. With that experience in mind, I just can't get too excited about cars with all the smog stuff. I do realize that this is where the money is when selling one of these cars and I'm glad that I kept the smog stuff in a box.

[61 vert]

Do you know if you have 840 or 291 casting # heads? How far does the block casting # predate the build date of the motor and the car?

[Keith Tedford]

The heads are 840s.

[Kurt S]

[ QUOTE ]
Ours was one of the last ones built in Baltimore and it had full smog. Sure made for disappointing performance. Once the headers were added, timing and jetting sorted out, it was a different car. With that experience in mind, I just can't get too excited about cars with all the smog stuff.

[/ QUOTE ]
Most of the difference is in the jetting and timing. They were optimized to pass emissions, not performance. Just fixing the timing will really waken up 68+ Chevy.