I agree with Blacksheep, I've done 2 motors with the SRM conversion, one failed after 13,000 miles, the small ball bearings started to break up. The 2nd motor has only 3000 miles on it so we'll see. I've spent a lot of money on these motors, especially the 1st one I did, and in hind sight I would have rebuilt the engine the standard way. I rebuilt my '54 GF without the conversion and it's been going for 7 years with no problems. If you change the oil regularly, the bottom end will last a long time.