LS coils - LS2 vs LS3 vs LS7

[BA.]

I've been searching forums quite a bit on this coil topic but still can't seem to tell whether the LS3 coils are different than the LS7 coils.

I realize that the LS1 coils are not as good, I realize that the truck coils are a little bigger, but have some heat disapating feature...either way I probably won't use truck coils.

So that leaves me with LS2, LS3 and LS7 coils. I think the LS2's are slightly larger than the LS7 coils. I'm unsure how the LS3 coils compare.

Should I consider an LS3 coil on my LS7?

These are a damn site cheaper than $660 from SDPC so you can see why I'd ask.
http://cgi.ebay.com/ebaymotors/LS1-LS2-LS3-LS7-6-0-6-2-Corvette-GM-Coil-Packs_W0QQitemZ170403724194QQcmdZViewItemQQptZMoto rs_Car_Truck_Parts_Accessories?hash=item27acda7ba2

[Andrew R]

I'm pretty certain they are compatible -it's just the brackets that mount them to the heads that are different. Truck coils seem to be the hot ticket lately.

Unless your doing something super high compression or FI you should be fine with any of them.

[WS6]

I'm not 100% certain on any differences between the coil packs in terms of their power/output/performance or whatever you want to call it. What I do know is they mount differently and have different connectors. Aside from that, for most people the LSx ignition system in 100% stock form is all they will ever need. So I would suggest getting the coils that will mount to the engine and plug into the harness. Don't worry about swapping around trying to find the best factory coil as they are all good including the LS1 coils. Get the ones that will be easiest to get working.

MSD's replacement coils work for the LS2/3/7 are all under one part number.

Have you checked with the local GM dealer to see if they list the LS3 coil as a different part number than the LS7?

[Jesse@SDPC]

The biggest difference in the coils is the ability to stay alive in applications where you need extended dwell. Turn up the dwell on an LS1 coil and you are lucky to get an idle out of it before you kill the coils.

[Kenova]

Just a heads up. I've seen two different types of coils on the truck engines of any given year. It seemed to depend more on where the engine was assembled than which engine was under them.

Ken

[TnBlkC230WZ]

The biggest difference in the coils is the ability to stay alive in applications where you need extended dwell. Turn up the dwell on an LS1 coil and you are lucky to get an idle out of it before you kill the coils.

Can you explain more? In what situations would you need extended dwell. I remember setting the dwell on my points but I'm unsure of how it is impacted here.

[Bow Tie 67]

Can you explain more? In what situations would you need extended dwell. I remember setting the dwell on my points but I'm unsure of how it is impacted here.

Coil saturation for a " hotter " spark. I maybe wrong but the only way I could see being able to turn up the dwell would be with a custom operating system. As you extend into a higher rpm range getting a little more dwell helps with combustion.

[Jesse@SDPC]

The only real applications where I have seen it prove not only useful, but also necessary, were in very high compression setups and setups running alot of boost. So, for the layman like most of us, there is no benefit. If I had bad coils or were shopping for my first set for an engine swap etc I would look for the truck version, then the LS2 version, and the LS1 version last, but if you already have the LS1 coils I would not look to the others coils for any benefit at all.