Yes...it is the lower passage that feeds the bearing. This is below the plug and feeds the rear main, the blind hole above the plug is the one that feeds filtered oil to everything else in the system. Oil from the pump divides BELOW the plug, a portion feeding unfilterd oil to the rear main, the remainin majority going through the filter, across to return to the vertical stack ABOVE the plug and on to the oil galleries. The rear main gets unfiltered oil straight from the pump.
The passage the ends before the rear main is the outlet from filter, the one below drilled from two directions is the rear bearing feed.
LOWER passage is into the filter, UPPER is from the filter. The plug forces oil flow through the filter and fully isolates the rear main from filtered flow. Except on racing engines with fully external oils systems, altering that is complicated, as Smokey demonstrates!
Probably not if used with original stock headers.In Post #57 wouldn't that set up interfere with the headers?
Interesting. I was just going to reinstall the "original" remote filter that came with engine, but it takes up room, and makes things cluttered IMHO. So, if running without a filter is fine, what should I be checking for exactly on the oil ports at the rear bell hsg on my C69?
I recall that story, but if recall correctly the failure was due to the fact that the owner had used a block that had been modified to have the oil diverted out to a filter and didn't realize it. He plugged the external pipe ports and the "grub screw" blocked the oil from entering the oil galley. I bet Bruce Lancaster remembers that one. I think he discovered the cause of the problem.
Bob
I am so thankful I found this thread as the engine I have acquired and am about to install has this mod. I was considering just plugging the ports (not knowing anything about that grub screw and the damage that would have occurred)
You guys are great and this site if very helpful.
the long and short of it any filter is better than none the debate will rage till the last flathead dies but if you dont have a filter youve got 0% chance of catching any contaminant your choices your consequences