Buying Tomei UEL used
 

Hi, I plan on buying a used tomei UEL header soon. It will come with no gaskets or hardware. My current stock car has only 5000 miles and is only 4 months old so there shouldn't be any rust or too much wear on stock parts. What all should I buy to install the UEL headers? I assume O2 spacer and the grimmspeed gasket(1 or 2?) are two of the things I should buy? Just want to make sure I do things right, thanks in advance!

You should buy the gaskets but skip the O2 sensor spacer if your intention is to do it right. You should get a tune that is calibrated for changing the header. OFT or a Tactrix cable will be the least expensive path as you can flash off the shelf maps with no additional cost on top of the hardware.

you may need nuts and bolts to connect it to the over pipe