I have attached a photo (I think) of the rear gear that shows the small lip on each of the splines of the shaft. I have tried to push the shaft through the gear, but the lips on the splines will not let it go through, even after a few hammer blows. It appears that the only way it will come off is if a grind down the ends of the splines, which doesn't make any sense, as this would ruin the shaft. It only makes sense as you describe that the shaft comes out through the front of the block, but again, it will not go through the rear gear. Thank very much for your help.....if I take the bare block to the metal salvage yard, the fuel cam and shaft may have to go with it.