How can one tell the difference in ignition Coils?

[BlueCollarTahoe]

got a p0300 code alreayd changed out the spark plug and wires, looking to swap out the coils but doing some research on parts there seems to be two, a square and a round type. How can you tell what you have? they more or less look all the same to me in the pictures and what i have in the car. more of an oblong shape.

2004 tahoe 5.3l v8

 

[Tonyrodz]

One is more expensive then the other. Post a pic of yours.

 

[YukonandtheHOE]

got a p0300 code alreayd changed out the spark plug and wires, looking to swap out the coils but doing some research on parts there seems to be two, a square and a round type. How can you tell what you have? they more or less look all the same to me in the pictures and what i have in the car. more of an oblong shape.

2004 tahoe 5.3l v8

The round ones have heatsink's, square ones dont.

 

[BlueCollarTahoe]

what does the heatsink look like?

 

[BlueCollarTahoe]

pic uploaded

 

[retiredsparky]

That aluminum fin thing is a heat sink. It helps to reduce the internal operating temperature of the coil.