I am having a problem this year with a few drops of oil dripping from my oil filter on my 383.It didn't leak last year after the rebuild but it started this year. I can't determine where it's coming from. The machine shop that did my block removed the oil bypass valve on the filter mounting plate and plugged it off. I have a high volume oil pump and my pressure when cold is around 65 pounds. Is it possible that I am building up too much pressure in my filter that some oil pushes past the gasket? I have already replaced the filter with the same results. No valve cover or sending unit leaks either.

70,
With the filter bypass blocked, it is possible that the extra pressure from the high volume pump is causing a leak. We normally do not recommend blocking the bypass on street vehicles because most customers will not take the time to properly warm up the motor before putting thier foot into it. Warm up is imperative with the bypass blocked and you should also be using a HP type oil filter, either the Fram HP4 (I believe) or one of Moroso's filters. They have much stronger cases and do not tend to flex as much. Ask Wally what happens when one of his customers used a standard filter with a blocked bypass, 1:filter came apart internally, 2:paper into oil passage, 3:motor toast http://www.chevelles.com/forum/frown.gif
The only other possibility I can think of is to examine the surface that the filter seats against and make sure it has not become damaged in some way, allowing a leak under the rubber gasket.
Hope this helps.

------------------
Bill Koustenis
Advanced Automotive Machine
Waldorf Md

You can sort of get away with blocking the by-pass if you run the 2 quart filter. You still need to let the motor come to temp, that means the oil not the water. The AC 2 quart filter is for a large truck with a 454 and I think the number is 832 on the filter. I'm with BilK here, on the street this is not to practical nor is that high volume pump.

The same car the filter came apart on had a Moroso 3 quart oil accumulator system. The car would pump the pan dry at 7500 rpm and the oil light would pop on in the lights. The system would inject oil back into the filter housing when pressure went low, saved the bearings many times. But in the end there was no excuse for the stupidity that ruined the motor.

70 Chevy,
It's TOOOOOOOOOOOOOOOOOO easy to replace that filter mounting plate. DO IT RIGHT NOW! They are so cheap and I bet your buddy will even give you one he has laying around. You don't neet it blocked on the street. If you just gotta have it for racin', change it at the track.

------------------