The shop manual specs a coil with a primary between 1.34 and1.55, and a secondary between 9,000 and 12,200. The PerTronix 40011 coil is specs at 1.5 ohms primary and 10,600 ohms secondary, so that part is well within the only factory specs in the shop manual. However, the PerTronix also specs a maximum Voltage of 40,000V, and a turns ratio of 115:1. These latter two may be a factor of the first two. A lower primary and higher secondary resistance would indicate a higher turns ration. Given that the existing coil specs at 1.7 primary and 6,960 secondary one might be able to deduce the maximum voltage and turns ratio of the existing coil but that would just be a speculative exercise in idle curiosity. I believe the most important number is the resistance of the primary as that is the only part of the coil that the electronic ignition circuitry is wired into, and seeing it is at the higher end of factory specs, it should work out fine.
Just curious- why not use this one?
This was the one that would crap out on me at any given time, once during the dyno test at the smog shop. It might be the original that came with the truck new. Very embarrassing. I had to scramble to swap it out for one that enable the truck to start again. Ah, sweet memories.
Talk to the referee
lol ā¦ been there, done that! My old VW Rabbit would stall almost any time I ran over a medium sized puddle of water. Ifigured the water was splashing on something in the HV system, so to figure out where I used a hose to spray water here and there in the engine compartment, even directly on the coil . The engine would never stall, not even a hic-up. But next time I ran over a puddle of water, engine stalled ā¦ lol ā¦ So thinking the problem must be that the water is splashing up, rather than down, I put the Rabbit on ramps and sprayed water on the idling engine and coil from underneath. Never stalled, never a hic-up ā¦ lol ā¦ Finally I decided to bite the bullet & start taking things apart, first the coil. When removed from the engine compartment and inspected under good lighting and a magnifying glass, voila, I spied a tiny crack in the outer housing. Coil replaced, no more stalling.
Dogged determination pays off.
I feel like a kid waiting for Christmas. Any thoughts on adding E85 to the gasoline to bring down HCs? Iām thinking 10-20% E85, and advance the time 2 degrees.
NOOO!!! donāt even think about running E85 on a vehicle NOT designed for itā¦
And I would pull/retard the timing 2 degrees from spec not advance it if anythingā¦
Use seafoam, marvel mystery oil or guaranteed to passā¦
And E10 is already hard enough on a carburetor, fuel lines and metal gas tanks with out adding even more E to itā¦ 
Got it, no E85.
Somehow I got it into my head to advance the timing to help lower HC out the tailpipe, but then I read this yesterday:
Why Retarding Spark Advance Reduces HC Emissions
Further searching confirms to retard the timing to lower emissions. Shop manual specs 7Ā° BTC. California allows 3Ā° variance, so setting the timing at 4-5Ā° BTC sounds like the way to go.
I will look into seafoam, marvel mystery oil and guaranteed to pass.
I really appreciate your correction on the timing.
Jack
You have to be careful though, I had an early 90ās Lincoln Continental FWD with the 3.8L catch on fire driving back from emissions testing from the cat getting so hot, I had retarded the timing 2-3 degrees and removed a small vacuum hose, but it passed lolā¦
Iād be extremely careful
My Mitchell 1 emission control application guide says the 1987 3.9-liter V6 has a timing spec of 10 degrees BTDC @750rpm for both auto and manual
There is a footnote for that model year . . . ECA module line disconnected & plugged. Transmission in Neutral
Please post a picture of your underhood emission decal
There are some vehicles out there which publish an EXACT timing spec, with no plus or minus . . . in other words, there are vehicles where you fail if youāre not right on the money
And the California max allowable HC for a model year 1987 LDT1 and LDT2 seems to be 63.1 for ASM2525 and 91.3 for ASM5015
Yeah I was thinking 7 BTDC was a little offā¦ but like you said, the sticker will say if it is still legibleā¦
Is it possible that Mitchell is giving info is for federal, not California? We are special here. 
I included the 2020 test that I passed. Canāt dig up 2022 on short notice, but it is very similar.
That year I failed terrible on NOx, Turned out the intake manifold port from the EGR valve was plugged with soot. I uses a 1/8 inch braided steel cable frayed on one end and mounted in a drill to clean out the passage. I think it was George_San_Jose1 who pointed me in the right direction on that. Retested and passed, but barely on HC, one part per million on both tests. The guy who tested me said I should buy a lottery ticket.
My cat was severely overheated due to bad choke. I had 219 on HC and limit was 220. Years ago. It was a 1983 car. Mitsubishi JET engine if I recall. Think it had a mikuni carb.
Iāll be dipped, it does say 7 BT(D)Cā¦ 
Now the timing is more important then the idle rpms (if close), the timing doesnāt start advancing at that low of an rpm anywayā¦ But I guess it had better be set correctly once you have it inspected being in Caliā¦ meaning, you can set the timing and then the correct idle rpmā¦
Yep, it is a ritual I perform every two years. Hopefully, armed with correct timing knowledge (retard, not advance to lower emissions), and the PerTronix coil, brass cap and rotor, and new wires I can skate through this time. Time will tell.
Jack
Thanks for the pictures
I would play it safe and show up with timing set exactly at 7 degrees BTDC at 700rpm, presuming you have an automatic transmission
I do have an automatic. What would be safe about setting the timing exactly at 7Āŗ BTDC, if I am allowed a 3Āŗ variation from the label, especially if retarding the timing tends to lower emissions?
@db4690 is of course welcome to speak for themselves, but I expect they mean that retarded ignition timing can cause engine overheating. Think about what happens. More complete combustion reduces HC out the tailpipe, but also produces more engine heat. One thing you have going for you, emissions testing is usually done with the hood up, which will help provide a little more engine cooling. Thereās a lot of idling during the test though, which can contribute to overheating. Make sure the cooling system is in good fettle, and that all the engine cooling fans that are supposed to turn on, do, and at the correct coolant temperature .
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Iāve always heard the Calif emissions testing folks allow a +/- 2 degrees range for ignition timing, not 3 degrees. In fact one of the test stationās staff I used to use would adjust my Corollaās engine to the maximum allowed retard, without telling me. But I was always watching what they were doing of course, so I knew, and would re-adjust soon after ā¦ lol . OP, are you sure about the 3 degrees? Who told you that?