It seems unlikely anyone's been in there at any point, especially since the motor only has about 55,000 miles on it. However....I did notice that there was no gasket between the bottom of the timing cover in the oil pan. Somebody had used a very thin coat of black sealant to seal that area, but it was done with extreme care, and the motor never leaked in that spot. Is there any chance at all this might have been done at the factory?
Black sealant was never used from the factory, someones been in there before. On a 440 the oil pan gasket(s) is all one piece, cork with rubber bits, the only reason the timing cover gasket kit has the short front section is that it gets pretty much destroyed upon disassembly. 2 gaskets are required if you have a HP 440 with a windage tray. Oil pan, gasket, windage tray, gasket, a little more work to get it all up there with the engine in the car. Permatex one gasket to top of windage tray, ya may want to do top of gasket so that it sticks to the block, sticky goo the oil pan gasket to the pan, put windage tray up in position and hope it sticks to block, (you can hold it up with a couple of the bolts F & R or middle what ever you can get to easily, then when you get the pan up close take the bolt out and you are right there to put the bolt in through it all, rinse and repeat for the rear) then quickly get the oil pan on before the tray drops. You can do it with the windage tray sticky goo'd to the pan but it a little more wiggly wiggly to get it around the oil pickup, easy to do on a engine stand, not so in car. No windage tray, pretty easy just make sure crank is rotated into the right position. Different technique's for different cars/jobs. Oil pan with single exhaust sucks too, drop center link AND Y-Pipe.
What I suspect is that someone did the job before and used sealant on the whole job, ie they probably didn't have a oil pan gasket and used sealant on the whole pan which would give you the no clearance that you are dealing with.
I did run into one problem, but I'm not too sure how serious it's going to be. When I was tightening the last of the bolts in the lower right hand corner, the fabricated gasket began to walk out from beneath the timing cover in that area. It separated from the block about 1/8", but ONLY at the tip of that one corner. It did not move out from the area where the bolts actually are, or migrate in or out from the main sealing surface between the oil pan and the timing cover. It also didn't split anywhere as far as I can tell.
I put a dab of sealant in that 1/8" gap, but will this be sufficient? I have no problem taking the cover off of this motor, fabricating a new gasket for that spot, and putting everything back together again. The last thing I want is to put it all back together and have it leak.
I'm not quite sure what you mean by "walk out" did the gasket shift or get squeezed out? From looking at the picture of the freshly painted timing cover I can see white stuff around the outer edges, I hope that isn't silicone sealer, silicone is slippery before it hardens and can cause gasket to shift/slide/squeeze out. Always use a tacky gasket adhesive and proper torque on bolts. A close up picture would help.
Nice job painting the cover... to bad you missed the bolts
not hard to do, just put the bolts into a old soup can, blast a healthy shot of carb cleaner on them, rattle them around for a minute and dump them out on a shop towel, let them air dry or give them a blast from the shop air gun. Grab some cardboard and punch a bunch of holes in it, stick bolts in holes and rattle can away. The heads will get a little socket roached unless you let the paint harden for 30 days, or bake the paint, but it will look a lot better than greasy black bolts like you have now.
Also replace that fuel line section(s), it's all wide open right now and your right in there.
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