[columbiA]

To find the leak,why not plug the overflow tube & pressurize the rad with abt 10 psi & with the pan off,you may see where its leaking.With the plugs out you could look in the cyls to see if any water there too.Could even be a crack in the upper part of the valve chamber. As for inserts vs babbitt,After almost 60 years of driving A,s Ive only had one brg failure.I was 30 miles from home when a rod brg suddenly let go.I was able to drive all the way home by useing light throttle & retarding the spark.There was hardly any babbitt left on the rod but the crank was not harmed.As for longevity of babbitt,I put over 75,000 miles on one A and no idea how many miles were on the engine before I got it. On my coupe Ive put 13,000 on it since I rebored it& replaced the valves lifters & timing gears.It is still running the original babbitt & I change the oil every 1,000 miles& dont add between changes.Still useing the original oil slinger.At 74,I dont think I will live long enough to wear it out.I always like to use old babbitt when ever possible,as I think it can be a crap shoot when you get a babbitt job done these days as there are not to many that can do the job properly.