I have a 03 Z manual Tranny, would like to purchase a spacer. I have read in forums the MOTORDYNE 5/16 is the best. Would like to know the main differences between the thermo and basic?

Hp gains?
installation ?
sound?
best???

 

get the basic

 

The Iso Thermal and Copper Iso Thermal reduces heat transfer into the upper and lower intake plenum and reduces assembly temperature by 30'-60'F. Cooler intake air temperatures increase air density and reduces the tendency for detonation or ping.

1) The basic spacer leaves the entire plenum hot all the time. (just like stock)
2) The Iso Thermal heats the plenum when you need it and doesn't heat the plenum when you don't need it. But depending on weather condition, the CCV must be switched on or off.
3) The Copper Iso Thermal is fully automatic. Just install it and forget it. It always gives the best results without adjustment. But it costs more.

So as for which one to use, it depends on you budget and objectives.

 

I have #3 that Hydra listed (Copper Iso Thermal). I love it. Installed (properly following instructions) and haven't had to touch it since. The benefit of running cooler temps in the plenum and never having to mess with a switch was reason enough to spend the extra money.