C4 1987 Owners Manual - Spark Plugs Alloy Heads.

[Vettech]

I would assume that most Vette owners in Oz would not have an Owners Manual esp if your car is a C4 between 84 & 92.
Google shows free downloads for OM's from early to 82 - then a big void - then 93 thru to now available one way or another.
Also I can see some differing opinions on the type of plugs to be used, since my 87 has alloy heads (not cast iron), it requires a different plug c/w a sealing washer.

The 87 was ready for rego in Dec'20, but it threw the P/S Pump, now thats fixed its running like a dog, throwing codes 33, then 34, then 33, also missing on a least one cylinder.

I can see at least one lead (#2) cross firing at the dissy boot to manifold, the leads hang everywhere with no rhythm or reason, so it may be time to shout the ole jalopy a new set of leads, plugs and wire retainers ?.

Any info greatly appreciated. I'll try Ponti World and/or Chev Parts on Monday.

So! - does any one out there know the correct type (pn#) for plugs for L98 c/w Alloy heads.

Also another point of interest is the positioning of the Dissy, the net, youtubes, googles and sales brochures show the top of the Dissy sitting square at right angles across the manifold, but my 87 (and 90 as well) have the dissy offset, I can only assume this positioing is in-correct, even though the timing seems to be ok !?!?!?.. This puts strain on the leads and causes them to be sandwiched in positions that rub, chaff and crossfire (like #2 cyl).

Any info welcome.

[Vettech]

Further to below - I believe the AC-Delco type FR3LS SUPERCEDED BY 41-629  Or NGK#5155 V power.
The AC is the basic plug at US$1.39, But these have been superseded by Platinum then Iridium, each supposedly better than its redecessor. (Of course they are a lot dearer here by over 10 fold.)

Whilst the AC-Delco R45TS, is for use in a Cast Iron Head engine.

Here's a Question - removing plugs whilst engine HOT or COLD, which is better ????.

[MY081]

Doug that is obvious if hot you will burn your fingers !!!!

[Kenobe]

  With the low melting temperature of Aluminium at 660 degrees I would remove them when cold to avoid causing any thread damage.
You don't want to have to remove the head to fit a helicoil now do you?
Threads bind up more often when they are hot and cause more damage so go and either boil the billy or grab a coldie and let it cool down a little. 

[Vettech]

Now I'm worried.

It seams that 2, 4, 6, 3, 5, 7 come out fairly easily, as long as they are not grown into the metal.

But 1 & 8 are an issue, I heard a quick mention on a forum that you remove RHF wheel, inner guard skirt and with multi bendy tools you can just get into #1, and eight may be better from under the car.

Any way its Canberra time, plugs can waite.