thanks that some good info!!

I think on the photo above the dohc is the same as the 24 valve SOHC. There were some changes between the 89-94 and the 95 24 valve,,,the 3.0 24 valve and the 3.5 got the same oil pump and you can see diferences in the oil pump mount.
Also mounting holes for the water pump is different.
From what I've seen over the years, the 6g72 sohc was the same block 88 Galant thru 94 Montero thru97 Hyunai Sonata. Diamante and 3000 had some block strengthening bosses added for the 10:1 engine and DOHC(see FrankR's supercharger thread).
After 90 they went to sequential injector system, dropped a EGR with the better performance,,,added heated O2 sensor ,,,improving emmissions too. TB was the same butterfly diameter 89-94. So I too think it was just improvement in the ECU/ inj system stuff.
Also note that the increase hp and torques are measure at much higher RPM on my chiltons charts.
Biggest improvement that I'm dealing with lately s the 92 on came with the much improved valve guides,,,which doesn't hae aything to do with this thread, butI just can't help talking abot it...
SORRY , I've got the midnight rambling going on <img src="/forums/images/graemlins/lol.gif" alt="" />