Well most of them. I just put in 7 of 8 tr-55's in my 94 z28 m6. I haven't got to the rear plug on the pass. side yet but I need to drop the y-pipe and starter maybe...its kinda tight on the top. The pass. front plug sucked to do, I could barely get it back in. Good thing I have small arms!! The car has been running bad so I am starting to replace things. The plugs and wires were changed right before I bought it but I wanted tr-55s in there instead, also I made the gap .040 instead of the .050 that was in it. The wires could be bad but they were replaced last spring. It just seems like a pain to do lol. I'd rather do the opti. I think it seems like a bad opti because awhile back I had antifreeze going all over it. Also when I'm driving it will just give a big surge/jerk. It acts like the car missing on every cylinder not just on wire.

I was thinking of making my opti vented using the following website someone else on here found, or should I just keep it unvented?

 

Also my car has a good amount of oil on the front of the engine..could be getting in opti..where could the leak be...timing cover or intake?

 

front main seals go bad easily on these. Mine has a slight drip in the front, usually ends up on the sway bar.

 

ya my rear main is leaking also...haha

 

My front main on the crank is dripping, the front pump on the trans leaks too. Has done it ever since I had the trans BUILT.

 

Btw nice car do you have any pics anywhere?? just curious.

 

Ok just got the back pass. side plug done this morning. It was a lot easier than I thought it would be. I had to bend the ac lines and egr line out of the way a bit, then I could barely get my arm down there. I'm going to have to stop working out or get headers if I plan on keeping the car lol. It also looks like I could do the wires by just removing the alternator too.

Btw all I did to change the plugs was remove the alternator. I did the whole pass. side on top, and the drivers was front two under and third was under and on top, and rear under I believe. You just need really small arms or get the wife to do it LOL.

 

Well I may not need an opti... I just took the car out after all plugs were in and it runs better than ever. The old plugs didn't look bad at all but they were gaped at .050. There is only a slight flutter sometimes.

 

what plugs did you have in it before? I just put tr55's in my car about 2 months ago and took out the bosch platinums I had put in there when I bought the car last august, and noticed a difference, though I have heard that our cars don't like the bosch platinums.

 

Most people try to stay away from the Bosch Platinums. They have a tendency to lose the platinum pucks over time. They'll pop off, bounce around and get lodged in your cats if you still have them.

 

They were ac-delcos gaped at .050. I thought they were fine but I guess I was wrong...maybe it was just the gap.

 

Gap supposed to be .050.

 

That is what they used to say. Now I've been reading around here and most say to go down to around .040. I also found somewhere that GM I believe said that you should go down too. The larger gap was for emissions and crap. Just what I've read.

 

yup, I know. My 97SS only has a couple thousand on engine. It came with Delcos and I switched them out with NGK TR55VX, which is a plat plug. The recommended gap. at the time was .050. So that is what they are gapped. Now NGK recommends .044. I don't know the reason.

I just know that usually the wider the gap the more juice required to light'em up, but more fire for the combustion process.

I've never had any problems with them at that gap. I also run an MSD ignition to further enhance the complete combustion, especially with gas prices today. I have also heard reports that the Bosch Plus 4s suck. I can understand that too, since it seems that with all those ground electrodes they would shroud the center trode thus reducing the exposure of the fire to the mixture.

So if you get the gap too close, you won't need as much juice, but you won't get as great a spark and may not get as effficient a combustion as with the proper gap and your mileage may suffer a tad. JMHO

 

I recently did a lot of work on my 97 M6. New plugs. Shorty headers. Motor mounts. Front seals and pan gasket. Electric water pump.
The electric water pump comes with a freeze plug for the weep hole. No more antifreeze all over the opti. And if I keep the A/C compressor on, the first radiator fan will run all the time. Weird about that. Another little LT1 quirk. But with the high volume pump and the fan on constant, it stays at 185 on the gauge all the time.
I had to drop the crossmember to get the oil pan out. So as long as I was this far apart, I did the plugs. I was leaking from the water pump seal on the timing cover, and also a very small leak from the crank position sensor. The sensor is an easy fix, just put some silicone on it. Not so easy with the rest of them.
I used a HD jackstand under the front crankshaft harmonic balancer to support the engine when I dropped the crossmember. Did all of this in the driveway. My mechanic friend at the local chevy dealer says its much easier on a rack. He was too chicken to do it the way I did!
I have pics of all of this if you are interested.