What's the Diff between the Iso Thermal and Reg Spacer?
 

Noob Question maybe, but i have searched and can't find any good answers.
Like the title states, i was wondering what the main differences were between the iso themal plenum spacer, and the reg Spacer.
Also which is better the 1/2in or the 5/16th's
Any answers would be great.

anyone?? I am wanting to get one for christmas and i need to know which one is best??

The difference is in the gains between 5/16 and the 1/2 . The 5/16 will give you better overall results, the 1/2 will give you greater gains at higher RPMs.

Get the ISO thermal if you live in an area where temperatures go below 45 F regularly.

from what i hear the 1/2 robs you of a little power at lower rpm's so if ur not planning on doing much to the car i'd go with the 5/16's and the iso thermal is for areas that experience colder climate. i have one in my garage i havent installed it yet.