In search for smog legal headers for my brother's 77, I came across the well-known 68601s, but also I found the hedman 68271 long tube headers! They are listed on this site http://www.arb.ca.gov/msprog/aftermkt/devices/aftermktdevice.php with an E.O. number! If you go to the summit racing website and look up the part, it shows a picture with the headers, gaskets, adapter for the EFE heat riser, and what looks like a fitting for the pre-heater hose that goes to your air cleaner. Do the 68601s come with the adapters for the heat riser and air cleaner pipe? Also the doug thorley 375Y-S headers carry an E.O. number too, but I'm not sure if those are long tubes or not. Anyone have any experience with the two headers I just listed?

And if you don't need the AIR tubes, you can use 68277 or 66277 headers, that are also smog legal. Just depends if you want the ceramic coating or not.

I looked this up for another member

Hedman headers

E.O. number D-167-26

Covers part numbers 66271 and 66277

E.O. Number D-187-7

Covers 68277 & 68291-6

BlackJack-Not sure if they are around anymore

E.O. number D-170

3021-s

Mr Gasket

E.O. Number 170-2

1021-s

Summit Industries, Inc

E.O. number D-540

376y, only 80-81 cars

You'll have to check to see if they are right for the car, I simply looked for second generation year range and Camaro. The database is a pita to look through.

On another note I believe MacDaddy said the thorleys fit like crap and eventually sent them back.

...Do the 68601s come with the adapters for the heat riser and air cleaner pipe?....
Yes, they do come with everything you mentioned.

Awesome, thanks guys! Now I just have to figure out if it will be possible to fab up a y-pipe that retains the stock cat position and still tucks up high enough to not scrape the ground on every little bump in the road.

Also the doug thorley 375Y-S headers carry an E.O. number too, but I'm not sure if those are long tubes or not. Anyone have any experience with the two headers I just listed?

I'm running the Thorley headers w/ air injector fittings on my '73- I forgot what the PN# is, but I'll check when I get home. These headers were a bit pricy, but I got lucky and found a new pair on discount at Tognottis a few years back- excellant quality & fit.

Cool, let us know if you have the 375-Y-S headers or not.

I looked through my reciepts this morning, but of course the header reciept wasn't in there. I'll check to see if there's a number stamped on the headers.

The number stamped onto the flange is:
375Y 071596

The number stamped onto the flange is:
375Y 071596

375Y's are long tube headers, But they are of the tri Y type not the 4 into one type. Ive been running the regular 375's, not the smog legal ones for the past few years. Nice low end grunt but they fall off alot around 4500 RPM.

Yeah, I figured the tri-Y's would make better power down low and true long tubes would be better for the upper rpm range. Where do shorties fall into this category? Are they that much of an improvement over the stock manifolds? Less power gain than true long tubes?