I put lots of passes on a 400HP 340 with a stock pan. It did fine until I put slicks and a converter in it, then it didn't have good oil pressure for the first 30ft or so. It never went to zero but it dipped then recovered about the 60ft. When I tore it down all the bearings were copper. I put a Milodon 7qt pan on and it fixed that issue. A friend of mine had a similar combo that did not heed my advice and he spun a rod bearing.