I have made an adapter fixture and a drive shaft to adapt an oil pump for a 250 inline six to the 216 and early 235 engines. The later model 235 pumps won't fit because of oil pan clearance problems. That's why 55-up 235's have a dogleg in the passenger's side pan gasket rail. From what I've been able to research, the clearance problem between the connecting rods and the oil pan troughs has two components- - - -the bottom of the dippers can't contact the bottom of the troughs, and the reinforcing ribs at the edges of the rod cap need to clear the sides of the troughs by a little bit. The top of the troughs can be ground down if necessary. Yes, the oil stream needs to squirt at an exact 90 degree angle to the pan rails so it hits the dippers as the rod reaches the bottom of its travel. Use a ball bearing and a pair of vise grips to widen the dipper if you choose to do so, but it's not really necessary if the spray nozzles are aligned correctly. That's when the load on the bearing is at a minimum, and the speed of the rod and the velocity of the oil stream forces lube all the way around the crankshaft, and out of the spit hole in the rod to lubricate the cylinder walls. Be sure the spit hole is clear with a small wire drill and a pin vise, but don't enlarge it.
There's no reason a Babbit bearing won't outlive a steel backed insert bearing, plus the Babbit can be scrape-fitted to the exact contour of the crankshaft and shimmed for the proper oil clearance, repeatedly. The original "soft" bearing material used in GM rods is so tough it will dull a high speed steel boring tool bit when I'm boring rods for insert bearings. "Reconditioned" rods use a much softer bearing material and must be adjusted more frequently. As with any other mechanical project, the alleged "mechanic" has to be smarter than the hunk of metal he's attempting to fix. That's becoming a lost art these days! Have fun!
Jerry
