AutoLite 103 and AutoLite 104, depending on how many stages colder you need

 

The local Autozone here carries them in stock. Just make sure you gap them properly.

And L67's have a ton of torque, a stock one could even do a decent burnout.

 

Definitely get colder plugs and tstat. Speed daddy headers are amazing! But the gaskets they come with are kinda poop lol i have 180 tstat 104 plugs sd headers k&n cai and custom 3" piping with flowtech afterburner mufflers. Res and cat delete and egr delete and im still wondering if 3.4 is too small a pulley lol good luck tho!