How we source our data

Specs come from GM/manufacturer documents where available, otherwise from reputable published references; secondary data is labeled.
Prices are from vendor catalogs on the date shown and change often. Always check the current price.
Fitment is taken from vendors' product listings and install guides. "Kit-verified" means we found a vendor kit for that vehicle.
Owner results (cam dyno numbers) are aggregated from public forum threads. They are exploratory: different dynos, heads, tunes and mods. We show medians and ranges and link the threads.
Answers are written from those sources, and conflicting sources are noted instead of hidden.