90 Head Swap

[R4G1NG_BU11]

I know the topic has been beat to death and I don't believe I'll get much of an answer here but I've searched through almost 500 threads and have spent hours trying to find information on swapping a 7 bolt head onto a 6 bolt motor that is in a 1990 eclipse. There is tons of information on putting it into a 2g or so, but I'm going in the other direction. I've read the writeup by Magnus and found it insufficient to my questions. I know I need the holes sized to 12mm, and the oil port mods for a milled head. But other than that I am at a loss as to what can be kept or if there are some other 2g items that I need to pull over into my 90 gsx. There has to be some difference as the head I have is from a 96.

 

[Timechg]

You need your 1g CAS and the 1g thermostat housing should bolt up to the 2g head and you can use the same water pipe that you already have. You can also change over the timing cover bolt plates that are underneath the cam gears. You want to keep your cams from the 1g because they have higher lift than the 2g's. The 1996 will have a cam plug on the end of the intake camshaft so you want to take that out to fit your 1g CAS in. There is also a bolt where the 1g oil feed line should be for your 14b, use your banjo bolt from you 1g head. You want to use a 2g Intake manifold (there is always this argument that you can put the 1g head on...but the runners will be way larger than the 2g head and may cause leaks).

 

[R4G1NG_BU11]

Thank you so much. Yea I have the intake as well. And i was hoping to use parts from the 1g head because this head isn't too pretty. Worth sending in as a core though. The turbo on the other hand is not a 14b. I think is a 16g though. Says TD05-H but that could be one of three. I plan on taking it off when I pull the head to actually figure it out because everything on this car has seen much better days. My biggest concern was that I would have to wire something new up sensor wise but if its as you say then its pretty straightforward.

 

[BogusSVO]

The 7 bolt head needs the head bolt holes enlarged to 13mm/.500/ Half inch.

The 6 bolt head bilt/studs are 12mm, you need some clearace.