First off, what size (mm) are the stock intake and exhaust valves. Second, when installing 1mm oversized valves in the head, what needs to be replaced? Valve seats? Guides? Or is it just machine work?

Built 420a
NER turbo kit T3/T04s ball bearing
AFX UDP
Crane 0014 cams

bump

tha fastest 420a eclipse in canada ( right Keith )

It is just machine work, redoing the seats to seal against the bigger valves. The shaft on the valves is the same size. I don't have the sizes committed to memory and am at work so I can't look up stock diameters.

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Firefly:
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valve head diameter
-----------------------
intake 34.67-34.93mm
exhaust 30.37-30.63mm

valve stem diameter
--------------------------
intake 5.934-5.952mm
exhaust 5.906-5.924mm

dsm/mitsubishi service manuals https://www.mediafire.com/folder/5k14qlaulb9s1/dsm_mitsubishi

service manuals(my whole collection) https://www.mediafire.com/folder/ac51jwwa3g1n1/automotive_manuals

Juggalo- nice avatar!

Who makes oversized valves for the 420a?

Built 420a
NER turbo kit T3/T04s ball bearing
AFX UDP
Crane 0014 cams

Blackdog - http://www.blackdogmotorsports.com/cylinderheads.html


ride__________95 Eclipse RS : 5 speed
power________Field SFC Hyper-R : Gude cams : Jeep TB : AFX UDP : ram air : test pipe : GST catback
suspention___Hurricane F/R lower strut ties : BOMZ F/R upper strut bars : ES inserts
sound________Kenwood KDC 5000 : Audiovox 8" sub toob - no sub amp(damnit!)
shizzle_______AutoCommand remote start : dual air horns : Caspers o2 simulator(rear)
incomming___Bosal header
Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html

95 Eclipse RS : 5 speed
14.76 @ 94.72mph
Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html