Yes the 2.3 oil fillers are at the rear. The 2.0 oil fillers are at the front if i remember right. Also i dont think the 2.0 has a sight plug in the timing belt cover to check on cam timing without removing the cover. Can also look at the distributor. If its got electronic ignition is for sure a 2.3, if its points its probably a 2.0 but could be a 74 2.3. If it was a 1.6 the intake manifold would be on the passengers side of the car, and the 2.0 and 2.3s have the intake on the drivers side. Hope this helps.