Hey guys,

Have been doing some research on coils and wires for my 3.8k

Coils
D576 GM part are for the supercharged 3.8
D555 3.8 K Engine

I've read, you can mod and install the D576 on a K engine, as long as you do all 3 coils, just higher output coils... anyone done this, true?

also, the GM wires
9746R Supercharged
9746U K engine

Wires, what'* the difference? just higher load rating?

advised to mod with higher output d576'* and Wires?

thoughts and input please


Thanks in advance

I assume the D576 is the S2 supercharged application coil, and the D555 is the NA application, based on the vehicle spans listed on RockAuto. It is my understand the S2SC coils fire a little hotter than the NA units. Coils should be a direct swap. Care should be taken to find a set of coils that are close to each other in resistance readings. Sometimes if readings are at the opposite ends of spec from each other, it can cause less than ideal behavior.

Plug wires are length matched for the necessary application, as one set has to go over a supercharger, while one doesn't. You should use quality wires for your application. Old word on the forum suggests that a good set of Beldins does good for even the craziest of supercharged applications.

Provided there was no preexisting issue, the gains from a coil swap are likely undetectable. You will notice more gains (namely restoration of power) from a good tuneup and cleanout than just the coils.

It'* mainly a good move if you have high mileage and are starting to get grief from the coils. My choice would be to pull them from a salvage yard yourself.

yes, from series II, same years

I had bought the generic coil 2 years ago, then 2 more a few months later

the first one, has failed, and i'm guessing, not long till the others go also

the output readings right now are 9.10, 8.10(newest), and 9.10

the wires were bought new 2 years ago too, but are the cheap duralast autozone.. it was just to get by, and actually ran fine till a few days ago, when i was getting a studdering going up hills, in overdrive, slight misfire feeling

checked coils and one was 6.64 and other two at 9.10 m-ohms

so i warranty it out, got generic new replacement for free

I also work at a parts store, i took in my meter and checked our bwd coils, and surprisingly, they tested at 5.54 and 5.75 m-ohms.. so we defected them out...

so, before i loose another, i thought about just buying the D576 coils, and the wires 9746u, and not need to mess around with them again

I had purchased 3 BWD coils and had one fail so I agree with R Jolly about going with a set of junkyard coils that you can test before you buy. So I have added BWD to the list of products that don't work well with the 3800 like Bosch and Airtex. I've had a Bosch fuel pump fail within 6 months(Airtex about the same) along with a Bosch platinum plus 4 spark plug causing a misfie

at the parts store I work at,
all airtex we sell, come back..all

I advise denso...but they usually take what is in stock, airtex..and regret it later