Gap them to specs per the op and you'll be fine.

Using bad grammar from my cell phone.

Spark Plugs
 

I am currently installing a downpipe on my car. I have the Denso Itv22 iridiums I believe they are one step colder and I have them properly gapped for stage 1+. Will I need a different gapped plug for running stage 2?

Gap them between 0.026-0.028 and you will be fine


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Fixed. 1/4" gap is a tad big.

AutoZone sold me a set of Bosch Iridium 9617 plugs. The electrode it's bigger than the stock FoMoCo ILTR6A 8G plug's. Can I use the Bosch or it's that dumb?

I had this happen with me when i got Autolites, they were just every so slightly bigger. I had to pick up a different spark plug socket cause even though it was the same size socket, the one I had wouldnt fit.