I would buy a short block.Power is made on the 2.3 in the head/cam.So I would take the head to a shop Have them shave the head first off each .020 is worth about 1/2 point CR.Shave to as much CR as you want.I wouldnt go much more than .080 You would be close to 10.5 to 1.Cam up to about 220/225 duration @.050 intake side (dual pattern is nice for stock exhaust mani)Would not hurt to port and polish things yourself before taking head into shop.(I have some nice pics if i had your e-mail addy.)Also if you are replacing the valves they sell the larger ones on e-bay all the time.And the last two things I would do would be go 2 1/4" or 2 1/2" exhaust(I run full 2 1/2" exhaust and a pacesetter header).And last but not least go with a escort flywheel it is about 5 lbs less than stock ranger,cheap at any yard.