gt-40p and thermactor air
 

The boys at Central Coast said they perform this mod. What does it mean, and my car will need this to run properly? Will it affect heads potential?
Does Summit provide this if needed?
Thanks for any info.

There is a thermactor passage in the back of each head. They are there for emissions. The GT-40Ps came on the explorers and are are set up to be an emission legal head. Some aftermarket heads don't have the passage and you would have to remove the smog pump and some of the stuff with it.
Having them won't make a noticable change in performance. I you need to stay emissions legal I would stick with it.

Glad to know, thank you.

One more thing: Summit sells them for around $538 and Central Coast for $638. Any reason for these being $100 more?
Thanx again.

CCM sells their heads with higher quality parts, especially the valve springs. I think the stock springs are rated for only .500 lift whereas the CCM one can go a little higher. Also the holes for the thermactor is an option with them. They usually don't have holes but they could drill them for you if you want to stay smog legal.

Or you could just drill and tap the head yourself. If you dont feel like doing that you could always just extend the wire for the air sensor and put it somewhere else.

http://www.nothingbutperformance.com sells the heads for 470 dollars.

If the heads don´t have the holes, I can´t leave them this way? No rough idling or bad working engine or check engine light? And the smog equipment can simply be discarded?
Sorry for so many questions, but I just trust the experts on this site (lol)...