2G 1G vs 2G head exterior differences

[Dylan94]

OK, so I have a 99 GST that supposedly has a first gen head on it. But after looking everything over it seems to have a mix of first gen and second gen accessories on the head. Like the thermostat housing and water neck is from a second gym in the cam sensor is second gen but the intake is a first gen intake.

Without taking the intake off and looking at the port is there any way to tell for sure what generation it is from the outside?

 

[19Eclipse90]

It’s likely a 2G head or 2G-esque as the 2G thermostat housing does not bolt up to the 1G head - the 1G head does not have provisions to accept the bolt pattern of the 2G thermostat housing.

Having said that, there are Hyundai heads that appear 2G in every way except the intake ports which more closely resemble 1G big ports. There have been a few occurrences of this popping up over the past couple years. Unfortunately, at that point, only way to know is to pull the intake manifold.

For reference:
1998 Eclipse GST engine swap with 97 GST engine
and
Questions about my 6 bolt.

 

[Dylan94]

It’s likely a 2G head or 2G-esque as the 2G thermostat housing does not bolt up to the 1G head - the 1G head does not have provisions to accept the bolt pattern of the 2G thermostat housing.

Having said that, there are Hyundai heads that appear 2G in every way except the intake ports which more closely resemble 1G big ports. There have been a few occurrences of this popping up over the past couple years. Unfortunately, at that point, only way to know is to pull the intake manifold.

For reference:
1998 Eclipse GST engine swap with 97 GST engine
and
Questions about my 6 bolt.

Fmllll ok so then that leads to my next question. Will my throttle body bolt up to the 2G head? And will the rest of the parts from my intake bolt up to my 2G intake? I’ve got one. But didn’t want to pull it all apart unless I know I have what it takes to put it back together seeing that the car ran fine with the set up the way it was.

 

[19Eclipse90]

A 2G throttle body will bolt up to a 1G intake manifold. And reusing the 2G throttle body elbow means nothing upstream of the throttle body needs to change.

If you mean accessories that are currently bolted to your 1G intake manifold transferring to a 2G manifold then no, coil pack, power transistor, etc., do not have the same homes on each manifold.

 

[Dylan94]

A 2G throttle body will bolt up to a 1G intake manifold. And reusing the 2G throttle body elbow means nothing upstream of the throttle body needs to change.

If you mean accessories that are currently bolted to your 1G intake manifold transferring to a 2G manifold then no, coil pack, power transistor, etc., do not have the same homes on each manifold.

So just because I have the intake I can’t just put it on and take everything off the old intake. So in other words I’ve got to run it like it is till
I have everything to swap back. Thank you!

 

[19Eclipse90]

Running it as-is would be the approach I would recommend.