I have the 7 bolt mitsu 4g64 from the 96-99 Eclipse Spyders and 91-98 Galants(i'm not totally sure, someone can correct me or verify).  It comes standard SOHC, however, mitsu did produce a few DOHC 4g64's and they came in production U.S. Galant's in 1994(once again, verification needed).  The DOHC 4g64 in the Galant makes 160hp standard, as compared to the 141hp in the SOHC Spyder.  But most of that power comes from the higher compression pistons(10:1, i believe) and the cams.  The DOHC does have the ability to rev higher than the SOHC, and that's the main reason i did my swap.  In my swap, i used a 1g 4g63 non-turbo complete cylinder head and mated it to the 4g64 block in my Spyder.  The reason i chose the N/T(non-turbo) head was because the cams are designed for naturally aspirated use and since my Spyder isn't turbocharged, there was no sense in using the head from a Turbo 4g63.  To swap heads, you'd need a  1) complete cylinder head, cams on down 2)Timing belt from a DOHC 4g64(the above mentioned galant is the only US car using it) 3) intake manifold and supporting acessories(Throttlebody, tb elbow, etc.) , And a list of other pieces.  There is a complete list of parts needed on the Yahoo's Group 4g64 forum and also on http://wraithnet.net/4g64/.  Many thanks go out to these guys, they really are the pioneers of this engine.  I was fotunate enough to have my friends 93 NT eclipse break down and got parts for free off it.  There are a few whole on the block that need to be plugged, not really a problem, but they NEED to be plugged.  I will be writing up my swap procedure in another post soon, and attach it as a sticky. 

Awesome.   you should destroke it a bit and rev Super High.. thats the first N/A Head swap Ive heard of.     Did it bump compression at all with eclipse Head?  on the 6Bolt Hyundai version they said it did to theirs because there was alot more dish in the hyundai head than the 1G head. 

 If you guy's are interested I can port match your turbo housings and ceramic coat them to promote less heat soak into your air intake track. I have seen a significant drop in engine compartment temps on my own veh wich helped drop intake temps . Also when I ported my exhaust  manifold and turbo housing it eliminated lag tremendously.  

 Thanks Mike!

1(248)249-5983 cell

    Let me know what you need coated it's based on material I have to use, and that depends on the part size. It's not very expensive compared to the gain you will receive. here are some average prices for general heat reflective coatings.

1) Combustion chambers and valve faces ( ceramic ) $ 32.00 ea.

2) Piston tops and skirts ( sides-moly bendum / tops- gold ceramic ) $35.00 ea.

3) Crank shafts 4 cyl eng. ( oil sheding reduces windage ) $ 125.00 ea.

Give me a call or e-mail me and we can work out some deals mjsanders22@hotmail.com or 1-248-249-5983 cell

Thanks! Mike

Sorry for the late reply, but Forcefed i have a question.  Will the Piston Top Coating(Gold Ceramic) make the top of the piston more resistant to detonation?  I'm gonna overhaul my engine pretty soon, and the prices of forged 4g64 slugs are still sky high.  So i was trying to find if there was a coating that would help the stock pistons through the rigors of forced induction.  I also have a new 7cm turbine housing that will be matched to a small 16g.  It doesn't need porting, but the coatings seem interesting. 

For spyderman, i got a pocketlogger for tuning.  It's absolutely great, it can monitor everything you can imagine and logs data.  Usually, i tune in second or third gear using my SAFC, depending on where i'm driving.  First i set the SAFC to the best combination i think.  Then i make a few runs and see how things are on the pocketlogger.  If the EGT's area outta range,i'll lean things out or richen them up.  I try and keep everything within the best range possibe, i'm not turbo yet so i don't really need to worry about a lot of things.  I'll be going turbo probably this summer.  I still have a few odds and ends to tie up.  My biggest obstacle is i have a first gen exhaust manifold.  I need either a 2g or evo manifold....but i spent my money on the 7cm turbine housing.  Plu, i need tires right now, mine are bald....really bald.