ok im gonna replace the icm, would i need to replace the pick-up coil as well or just the icm???plus would that give my blazer the short it has now???? and also why would one store have them anywhere from 30 to 70 $ cheaper???? its not on sale or anything

 

Quality would be my guess as to why one is cheaper than another.

These are High Performance engines, buy the best quality you can buy. Not saying to waste your money on overpriced parts, just buy the best quality part you cna afford.

No need to replace the coil. However if you do, same applies.