QUESTION: Will these fit a 5.0? Yes
QUESTION: Do they need a extra gasket? No
QUESTION: Is there any performance gains? No
QUESTION: Will it effect my fuel economy? No
QUESTION: Which side does the small hole go on? Does not matter
QUESTION: Can I open the hole up? Yes, may be necessary for your mods
QUESTION: If I am not happy with this can I get a refund? Yes, once you mail it back, minus my mailing fees
QUESTION:
QUESTION:
QUESTION: My idle is always high, will this fix it? No, you have other issues
NOTE: The idle will be higher until motor reaches normal temp