93 LT1 trying to get the heads off in the car. There are two bolts that hold the "coolant air bleed pipe" to the back of the heads. 15mm is too big, 14 too small. Anybody know what size that sucker is? The FSM says nothing about bolt size. I am starting to round the head off with 15mm (fits really lose) also 5/8 is too big, 9/16 too small, have never seen anything like it? HELP!

Use a 6 point 15mm socket.

Another challenging bolt. It is supposed to be a 15mm IIRC however the flats of the factory banjo bolts are cut at an angle and very difficult to get a socket to stay on.

This is what I did... You will get a kick out of this.

I left the crossover tube on the heads and pulled both heads off together. Then removed the banjo bolts with the heads on the bench. I didn't even bend the tube. And I pulled them off by myself too. That was interesting to say the least. IIRC I butchered them up pretty good getting them off after 150K miles. I replaced them with new ones GM Parts direct. However I think they are Out of Stock now, but you might want to check.

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O MAN! I was just going to cut the tube in half, I like your idea much better. Thanks for the tip!!
Hey didn't you build a 383 recently? How did it turn out? Any tips for a rebuild?

You could cut it in half and then use a high temp hose to reconnect them but I'd salvage it if you can. You can find them on eBay and other places as well. They are getting hard to find but not impossible. Also we can use the steam tubes from F-Body Lt1 and just cut and bend the end that goes into the overflow line.

Yes, my 383 is complete and so far running really nice. Lots of power. I like being able to punch the gas on a fast roll and have the tires lose traction and the rear end get get loose. It never would do that before! It will chirp the tires real good when it hits second gear if I romp on it good. This is with the A4. Pete did a good job on the transmission as it feels nice and tight.

Don, did you use a balanced rotating assy. or assemble pieces? How much of the work did you do yourself? What pistons did you use, rings, connecting rods? Is there a page on the forum with your build, I would really like to look at it? What heads?Thanks

Tom,

Yes, my builder used a internally balanced cast Eagle rotating assembly with Mahle Perfect Circle Rings, forged Sealed Power pistons and Clevite bearings. Rods were I beam forged but I can't remember the mfg, Eagle because it came as a balanced set IIRC. I did not build it myself. All I did was take it out and drop it off. After many conversations and me sitting in the builders machine shop a few times we nailed down what it was I wanted and would need to keep me happy and try to keep the engine build within my financial goals. However, we wound up doing some really wild stuff to the heads because the original valve guides were hosed on one of the heads. We used the stock LT1 heads but wound up going with .205 intake valves. The seats were replaced and reground and new valve guides where installed. Lots of bowl work and porting to accommodate the bigger valves. He also chamfered each cylinder top to allow a smoother transition for gases to enter the cylinder and not hit the edge of the cylinder and cause turbulence. It wound up with 10.8:1 Compression but I'm not sure what the power is at this time. Probably between 350 and 425 to the wheels. I have no clue. That may be wishful thinking too.

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Don, nice looking build, thanks for the pix. I think I will go back with the 355 in my rebuild, just don't need that much hp, after the hot cam, and headers I am already on the verge of traction problems especially around any corner and I have 315 Nitto 555s.

I'm glad I read this article about the "steam tubes" as I will be pulling my heads for an upgrade this fall/winter. It's looking more like I'll pull the motor and then pull the heads. Do you guys disconnect the tranny from the engine (at the bell housing) and then pull the engine or do you pull the tranny then pull the engine?

I removed mine with a 15mm twice with no issues. I wonder why a 15mm is not working for you.

FYI, you can find those rubber gaskets at the dealer

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The bolts were very corroded, the head of the bolts is slightly tapered, a 15mm works fine when the heads are off the motor (that's how I got mine off) but when on the block, impossible to get off. I am glad the dealer can still get them, hope that is still true.