[Porchev]

Sorry for being such a Chevy newbie!

Some questions:

From the block number, I believe this is a '77 350. It has been built up in the past, it has aluminum heads, but I can't tell much more about it, because I don't have the records.

1. Is the vacuum pot on the distributor an advance or retard?

2. What is the "T" coming off the distributor vacuum pot line for? As you can see, it comes off it, into the blue and orange plastic thing, through that big grey plastic thing by my finger, into the "T" coming off the valve cover breather, and into the carb.

3. Why are the vacuum line and the valve cover breather T'd like that?

4. I assume the gold pot on the manifold is the EGR pot.

Can I get rid of some/all of this stuff. The EGR pump is gone so the system doesn't work anyways, there's no smog requirement in my area, and it's added complexity I'd like to clean up if I can.

[trees]

Strange vaccum plumbing. I'll address the EGR pot (valve). Remove it and cap off with gasket and metal plate. Plug the vaccum port on the carb. The orange and blue thing near the end of your frindship finger is a check valve as well as the blue and yellow thing near the vacuum advance unit on the distributor. I have no ideal why the vacuum loop near your finger is installed. I would take the large line from the PCValve directly to the large port in the front of the carb base. The large port in the intake manifold near this carb port is normally the best source of vacuum for power brakes. I can not tell from the picture for sure, but it looks as though both of these ports are caped off. Back to the vaccumn advance unit plumbing: I would leave the check valve in (near the unit) and run that line to a port high on the carb. The unknown loop would go in the holding bin, waiting to make sure every thing works as advertised and then into the trash bin. There is a bunch of other metal plumbing in there I would get out of the way as well.

Trees

[novajohnb]

The EGR valve works by recirculating exhuast gas into the intake to lower combustion temperature (the inert exhuast gas takes up room otherwise occupied by air-fuel mixture.) This lowers NOX emmissions by virtue of lower combustion temp.

If you remove the EGR valve, you may make the engine more prone to pinging/ detonation due to higher combustion temps.

At WOT, the EGR valve will not influence performance, as it will not be open if hooked up correctly.

Your best bet is to locate the vaccum diagram for the car- usually on radiator support underhood. All of the components will be shown along with vaccum hose routing.

[Porchev]

Thanks all.

This engine is in a converted Porsche. So there isn't a lot of stock info to go by.

It had the smog stuff put on it a long time ago to pass smog (10+ years ago), but smog hasn't been required for a while now and the system is non-functional. So I want to remove the remnants.

Any other info appreciated!

[poncho62]

If no smog test is needed, I would get an early Performer manifold with an Edelbrock or Carter carb. Then you can ditch most of the vacuum lines etc.

[jesse01]

Originally Posted by trees

Strange vaccum plumbing.

yes it is. but my question is = is that electrical tape on the fuel line? lol

J