What are the chances...

[76GMC1500]

... of having a warped pan rail on the underside of the block. I've had this recurring oil leak on the front passenger side of the oil pan, right under the fuel pump. I've replaced the timing cover gasket once, and the timing cover second. I've replaced the fuel gasket once and the fuel pump a second time, and again the gasket (my dealer is cool enough to give me small parts like that for free and it takes 2 minutes to change), so I know the leaks are not coming from there. The only other gasket in that area is the oil pan. What ends up happening is my engine is a little worn out, so it pressurizes the block a bit with blowby. When I'm going up a steep grade at 65, sometimes it squirts some oil out of this corner of the oil pan. The problem is, the fan and all of that air blows it back onto the exhaust and I get a cloud of smoke that comes out from under my hood. I replaced the gasket with one of those neoprene ones from felpro and that worked for a few weeks, but my pan rail was warped. I pounded it flat, and reinstalled everything. The leak was fine for a few months. I bought a new Milodon pan, and that sealed up nicely for a while longer and the leak came back, but not badly. I pulled the pan and put my new oil pump in, and everything sealed up ok for a few more months. Well, last weekend, it came back worse than ever and now I am thinking the pan rail of the block isn't straight because I know I am doing things right when I put the gaskets in. The rest of the engine is dry. I guess I'll ditch the neoprene gasket and get some corks and coat them generously with RTV.

[MrMopar64]

I'm not sure what your working on but I've seen talk about some GM stuff having a bolt to hold the fuel pump pushrod when you have the pump out and where that bolt is they tend to leak cuz guys forget about them..... I've seen post where they look a long time before they discover where the leak is
Something to check

MM64

[76GMC1500]

A bolt eh? That would have made my life easier. I just put a whole lot of assembly lube on it and hoped it created some suction.

[FASTCHEVY]

Yeah my frend showed me that little trick, I thought he was crazy. There is two holes (on my block) and the bolt goes in the lower hole to stop the pushrod. Use a short one to plug the hole. Mine didn't have a bolt in it, but it didn't leak.

[76GMC1500]

Yeah, I got both gaskets, and if you get them from the dealer, they have sealer pre-applied. Where is this bolt hole you mention? My truck is up a very steep hill from here, and I don't feel like climbing the stairs until tomorrow.

[MrMopar64]

Originally posted by 76GMC1500
Yeah, I got both gaskets, and if you get them from the dealer, they have sealer pre-applied. Where is this bolt hole you mention? My truck is up a very steep hill from here, and I don't feel like climbing the stairs until tomorrow.

I think it is right above the fuel pump mount but not sure I've not had this problem myself I've just followed threads on this....
I know it is along the path of the push rod for the pump

MM64