looking to install a steering wheel quick release hub on my '72 240Z. I want to install a spline type (not the hex) with the finger tip release ring and not a pin release. They seem to come in two sizes, 5/8" and 3/4". Which size fits the Datsun best? (since I'm sure its shaft is Metric) Which brand is recommended? Since I thin the spline hub has to be welded on the shaft and there is a bearing right at the end of the Datsun shaft, how can I keep that bearing protected from the welding heat?