The coils are different. Because the ICM is different. The ICM is different because it won't bolt to the new L67 bracket because the the thread pitch is different.

 

I am not sure I follow what you are talking about

The ICM on the L36 and L67 are the same exact unit (same part number and everything). I've verified two factory units side-by-side. But the bracket as mentioned for the L67 and L36 are different. The ICM on the 3100 and 3400 are different from the 3800.

The coils GM used on the L36/L26 3800, 3100 and 3400 are exactly the same coil. The coils used on the L67 are NOT the same (physically they look identical, but they have different part numbers and deliver very slight improved throttle response).

 

If they will really give my more throttle response then I will changed mine and give you my opinion on that subject .. Cause I have them both for the TOP SWAP!!