I’ve been hearing that oil pan leaks especially from the front and back seals are just something you have to put up with and keep watching your oil level for. I want to go to a single gasket type but they say that is better but still leaks. Are they right? I should know from all my Chevy’s that have all leaked but was wondering if there is a cure for it somewhere out there in rumorville.

 

A one piece gasket and a small bit of RTV in the front and back with the correct amount of torque on the bolts should never leak.

 

They really shouldn't leak. You have to take extra steps to ensure a good seal; part of which is flattening the pan rails after previous owners & mechanics over-torqued the bolts and bent the rails.

 

Agree with above, flatten pan rails. Make certain you know if your pan uses the thick or thin ends. A dab of silicone in the corners and a really good Fel-Pro one piece pan gasket.
I like the ones that come with those EZ install plastic pins.
Now, rear main seals....... don't get me started.

 

Ditto....let the new gasket seat well and let the silicone sealer cure at least 24 hours before adding foil to the sump!

Use a granite counter top to lay the pan upside down and look for bent areas...mark the bent areas with a marker and flatten the bulges. keep repeating the process until the pan sealing area lays flat on the granite counter top.

DON'T USE THE COUNTER TOP AS A PLACE TO HAMMER THE BULGES FLAT!!!

 

I had a new very expensive pan and it leaked with the one piece seal and it was checked flat....I added a thin coat of black RTV to both sides of the seal all the way around. Doesnt leak. not using a sealant on a flat gasket is hit or miss if it will leak. A bit of Ultimate black goes from a 50/50 chance to 100% it will not leak. The rear main is another area of leaks that definitely needs more than just the corners. I would rather use the rtv and not have leaks than to do it twice and the second time is a hassle if the engine is in the car to test it

 

So that is hopeful from what i'm hearing here. Doing it with the car jacked up using floor jacks may not have as good of results as doing it with the engine out of the car or 2nd best on a hydraulic hoist in the car?

 

Keys to getting a good seal:
* recommend using a composition gasket of cork and neoprene or the one-piece gasket.
* use wood blocks and hammer to flatten any bent, warped areas between bolt holes on the pan surface if still using a stamped pan; if using a chrome plated pan, sand the gasket surface with 120-150 grit paper in a swirling pattern.
* clean the gasket surfaces, the block surface and the pan surface with lacquer thinner or other good volatile cleaner to get all parting compound, oil, grease removed.
* DO NOT USE regular silicone sealant ANYWHERE. If you want to put sealant in "joint" areas, use Permatex Black RTV sealant only -- it is made to seal petroleum products.
* use two threaded dowels (or bolts with head cut off and shank rounded a bit) at opposite corners of the block sump area to guide proper location of the gasket and pan when they are installed. Hand install two more bolts at opposite ends, then remove the dowels.
* DO NOT APPLY FULL TORQUE TO ANY BOLTS WHEN FIRST INSTALLING THEM. First round: sung all bolts down with little torque; then apply about 1/3 of full torque value fully around the sump; then apply 2/3 of full torque; finally, apply full torque to all bolts. NEVER OVERTORQUE ANY SUMP BOLTS ON A STAMPED STEEL PAN.
* Drive car at operating temps for an hour or so, then retorque all pan bolts to full torque again (at heat, gasket will continue to compress some, relaxing original torque values).
Your pan should be dry and leak-free.

 

I agree with the above recommendations. I had to replace my oil pan gasket after I scraped a large speed bump that left a little yellow paint on the bottom of my pan. It broke the seal at the back of the pan and caused a slight leak. I put it off for quite a while but eventually put it on jackstands and crawled underneath. Not quite as easy as it was 40 years ago. The Corvette is actually one of the easier cars to do the pan gasket. After making sure that the holes were flat, I bought a couple of reinforcement pieces for the ends. After looking at them I thought that if reinforcing the ends was good then perhaps doing it to the entire length might even be better. I went to a hardware store and bought some steel strapping material. I don't remember the thickness, but perhaps 1/16 to 1/8 inch. Fit it to the pan and marked where the holes needed to be and then drilled out the holes. Painted everything and reassembled the pan using a Fel-Pro one piece gasket. Put it all back together and it is oil tight. I don't know what other think of my solution to keeping the pan rails flat. I also removed the starter to do this. Theoretically, you don't have to remove the starter, but getting the bolts back in during installation is easier with the starter out of the way.

 

Load-spreaders are a good 'tool' to prevent warped surfaces on stamped steel pans/covers. That's way Chevy used them on all the early V8 valve covers. As mentioned, some of the SB oil pans had load-spreaders at the corners. Very useful, when needed.

 

Other than the great suggestions in this thread consider that Early 327s had a smaller diameter front radius on the oil pan than later 350s. Other than the different front radius the oil pans are interchangeable. Any gaskets you get need to take this into consideration. Adding to the problem is the possibility that a 327 may have a replacement oil pan with the larger front radius. Even if you order the correct gaskets for the 327 it will leak at the front if you have the larger front radius pan.

 

Not necessarily a 327 vs 350 thing.

 

You have to use the gaskets appropriate for YOUR hardware. That may NOT mean what was stock for that model year, as prior owners may have installed non-stock hardware in the vehicle. As mentioned above, different year "pieces" required different gasket sets.

 

You have the original style 5qt oil pan?

Original style timing cover?