Ok. Ill make my purchase on ebay right away. Shipping does affect the overall price sometimes.

"Made in Japan" for Z guys means 100% perfect fit and function.

On 6/12/2018 at 9:55 AM, Mark Maras said:

 I'd buy them. I like the idea of brass contacts too but in reality there is only one "contact" point in the center of the rotor. The precise placement of the rotor and the precise air gap between the rotor and the plug wire  "contacts" are the critical factors IMO.

Well i made my order on ebay of both parts. Hope it solves the 4h cylinder issue of getting the ngk BP6ES spark plug black during idle at stop lights and traffic jams. Anyway i did a compression test yesterday with the engine cold and all cylinders measured 100 psi. So there should be no problems. 

Mechanic says in shoulf get an air conditioner or washing machine hose and tie wrap it to the mouth of the orange airbox and the other end through one of the holes near the air dam so it can suck fresh air at idle and avoid this situation. What do you think

 How is it doing these days when idling in traffic? Still overheating or loading up the plugs? Easy enough to add a hose but what "situation" is the mechanic trying to solve with the extended air intake? 

 The compression test looks wonky to me. First, I've never seen identical compression in all cylinders in any engine. Second, If they're all at 100 psi, IMO, they're all low. My engine tested around 160 psi (+ or - 5 psi.) the last time I checked.  is it possible the valves were set too tight?

Should the compression test be done after running the car or with the engine cold?

Mechanic says the carbs could suck fresh air at idle instead of the hot air trapped under the hood during idle and it could help avoiding the plugs getting sooty

These plugs are sooty? 

No.

1 hour ago, jalexquijano said:

Well i made my order on ebay of both parts. Hope it solves the 4h cylinder issue of getting the ngk BP6ES spark plug black during idle at stop lights and traffic jams. Anyway i did a compression test yesterday with the engine cold and all cylinders measured 100 psi. So there should be no problems.

Those numbers do not sound right. Back further in this thread you posted a test from 2015 that showed 180psi to 185psi all the way across.

That would show a very healthy engine. If the new numbers are now correct then something happened and needs to be corrected

before any further tuning can be done. It would be fruitless.

Big cam can lower compression results as well as valve timing and no lash

1 hour ago, 240260280 said:

Big cam can lower compression results as well as valve timing and no lash

 It was 180ish psi last year. Something changed. Assuming the cam wasn't changed nor the cam timing, I'm guessing the valve lash is too tight too

@jalexquijano Time to check the valve lash again if you're sure the 100 psi compression test was done accurately. Yes you have to. Valves that aren't closing all the way will be burned toast in a very short time. On the plus side, IF, the 100 psi was correct jumping it back up to 180 will feel like you slapped a turbo on it. After checking the valve lash do the compression test with the engine warm. Start with #1 and go thru all six, then test all six again to verify the first test results. A written explanation of the 100 psi compression test procedure might help explain the low numbers.

Some compression testers have crappy hoses from China that expand like balloons and show lower pressure.

Also opening the intake is good for a few extra psi