I myself just built a 2.4L G4CS Stroker w/ the DOHC 4g63 head bolted on and came to the timing belt. I had ordered a 4g64 belt, but instead I had in my hand a 4g63 belt as i was sent the incorrect one. Mind you this is a saturday night, and I do not want to wait another week to get another belt so i try like hell to stretch the belt over the gears and all. I did actually force it on, although it was hideously tight, so tight when i pulled the pin on the BRAND NEW hydraulic tensioner, it did not move I could put the pin right back in. BAD Anyways.. on to the fix. Take off your swinging arm that your hydraulic tensioner pushes against and take it to the bench grinder. You can grind about 1/4 inch of material from the bottom pad, and put back on. This makes putting the belt on a good bit easier . On top of that you can time the car w/ the MHI timing belt install kit (to tension the belt correctly) and measure the extension of the pin after 15 mins and everything turned out in spec. after rotating it the 6 times to verify timing, and letting it settle I checked the belt tension by hand above the cam gears to verify it was not obnoxiously tight and it feels the same as the belt on my 2.0 does. So there you have it a verified case of a 4g63 belt used on a 4g64 with the correct tensions applied to the belt w/ all new parts(not worn out) and everything came back in spec installing the belt by the book(w/ the slight mod).. Now we can easily attain a kevlar belt and stop worrying so much about timing belt failure. Good Luck!