My '01 5.3L came with the square coils from the factory, but I just bought a set of round truck coils with heatsinks from the member to use with my Taylor GTO spark plug wires (too short for the square coils). The truck is NA at the moment, but I have plans for a front mount turbo, looking for around 600rwhp and up to 15psi. I got the GTO wires because they have a 90 deg bend to keep them away from the turbo manifold.

First question is, will the round coils plug straight into my harness without modification? I bought the coils with the bracket and sub-harness that connects each coil to the big 2x4 connector.

Second question is, are these coils an upgrade or downgrade to my stock square coils? I figure the heatsinks could only be a good thing. They also have less miles than my stockers.

Thanks!

 

10 seconds comparing the two different styles would have gave you an answer. They are neither an upgrade nor downgrade.