I have now removed the alternator and used the bolt to seal the end of the shaft, what sort of oil presure is there at the small starter ring hole? and what sort of tempreture does the crankshaft get up to at this point, the reason i ask is, while searching for something suitable to block off this hole i came across a hard plastic tube, which was a perfect fit, but would it melt? the tube i found was a sterident tablet container, but wont use it if crank gets to hot, i will have a collar turned down and use that, but to find something as simple as this was a bonus, what do you think, will it be safe or not.