i was installing my new gauges yesterday when I noticed a metal tube/outlet at the rear of the motor, below the distributor, not connected to anything.....what is this and where does it hook up to? do I need to hook it up?

 

On SBCs from 68 and earlier, they had a crankcase breather there, and no PCV in the valve covers. There was an in-line PCV valve on some of them.

If you have a PCV system in your VCs, plug the one in the block.

 

Yeah I have the pvc in the valve cover.....ill block the tube, thanks
Ron

 

Ahh... The old road draft tube. Best oil leak Chevy ever engineered. And when the PCV first appeared, how many people wanted to disconnect it because it was thought to be a "pollution control" device? Frankly, I like the cleaner oil and crankcase, but that's just me. A little like a 20-year old version of the misconceptions about the EGR system, wouldn't you think?

 

You got that one right...and talk about a tough place to get at.
Hey Vader, what ya think of World SportsmanII heads 64cc, along with a comp 280 cam on a 327 .030 flat top forged pistons, Forged crank (stock) with splayed caps, running a 3000 stall. Think this would be very streetable. Also would the 600cfi Edelbrock on the RPM Intake be enough to feed it? What ya think?

 

That should net about 331.6 cubes. Using theoretical displacement and presumed flow through decent heads and 2.02 valves at those lifts, the 600 CFM carburetor should feed the engine through 6,500 RPM before there is any concern of restriction. It's probably going to idle like crap, however. It's a good thing you're bumping the stall speed of the converter to take full advantage of the extra RPM you can run. I hope you have a stout drive shaft and rear end.

You might still want to clean up the casting flash and polish the exhausts and chambers of the heads before you install them. This engine is going to be all about high RPM flow, so every little bit is going to help.

You are balancing the bottom end, right?

 

Back to the road draft tube: For a year or few, the factory used a little fitting to replace the tube for the PCV valve function. When I moved from Nebraska to California in 1986, the left-coasters made me convert the then-original style 283 to PCV using one of those fittings. Charged me $35 for a "conversion kit", which contained that stamped metal fitting (probably from a junk yard), an oil fill cap with a tube fitting, a plastic elbow fitting and grommet for the air cleaner, and a couple of feet of rubber tube to connect it all.

Remember PCV requires two paths: one out - the PCV valve connected to vacuum; and one in - later styles used a tube up to the air cleaner with a filter, but a breather cap works fine for non-emissions applications.

 

Hey 5-7 long time no see....So what you are saying is I need a breather element in the other valve cover since I have the PVC in the other, and still keep the air tube blocked? I have the edelbrock sig. series valve covers, with the chrome oil filler cap, does this also act as a breather or do I need an actual element type?
BTW, the complete 400 deal fell through, what I ended up with is a 400ci short block.....long ways to go on that one, I decided to upgrade the 327. Ive since bought the transgo shift kit and corvette servo, and I will have the 3000 stall this week. The heads have to wait till I get healed up, anyway , good to see ya.
Ron

 

what kind of times are you running with that 327? i just bought an '84 with almost the same setup but with full length headers and haven't run it yet. the rear is out now getting 3.73's, a mini spool, axle tubes welded, etc. thanks in advance

 

You want to vent the engine as much as possible. You need at least one breather. They "Mr. Gasket" make some that actually replace the filler cap and still leave it useable.

 

I havent had this car to the track yet. I'm waiting on a higher stall.
The motor was in a Monza before running mid to upper 12's. It's fast....loves the high RPM's. My biggest problem is keeping traction. when it hits 2nd gear at 6-7000rpm all hell breaks loose.