SBC oil pan information.

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Irishman999

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305
I thought I would get this on the Interwebz in hopes of helping the next guy that might run into problems similar to mine. If anyone has info to add please do, hopefully this pops up in a search engine to those that were as confused as me.

First variable in the oil pans is single piece rear main and 2 piece rear main. The engines with a 1 piece rear main seal have a bigger opening on the back so obviously you cant mix pans or gaskets between the two styles. One piece rear main seal style started in 1986.

If your oil pan is the style on the left shown in this picture and also a one piece rear main get ready to buy a new pan.
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This is why

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I searched all over town at multiple parts stores for a gasket that fits a 1 piece rear main seal and has two holes in it for dip sticks. I found a gasket with 2 dip stick provisions and got home to discover it was the 2 piece rear main style and did not fit the pan. I finally ended up at Summit racing because their website showed the exact gasket I need. When they fetched it out of the warehouse it only had 1 dip stick provision just like the one Autozone sold me earlier. As a matter of fact we looked at all the gaskets styles they offered with no luck.

The solution is to buy part Number: SUM-G3503X

Heres a link: http://www.summitracing.com/parts/SUM-G3503X/

The new oil pan will have one provision for a dipstick on the passenger side and uses the gaskets you can find at any parts store.

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The new pan is a different shape than the old one, but it will work even with these two dip stick holes.

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Another issue you will run into while switching oil pans is these strips that spread load over the pan. The side that is now straight needs to be modified to fit. Where it curves out to go where the old dip stick provision needs to be cut before you try bolting it to the pan. If you are to lazy to grab a cut off wheel you can do what I did and just grab the strip with vice grips and bent it until it cleanly breaks off. Make sure the strips are straight before trying to install them.

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Irishman999

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Here is where things get weird, I installed the regular gasket I got and the truck started leaking oil out of the front of the pan. The oil was coming out where the pan meets up with the timing chain cover and steadily dripping down this hose.

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I read through alot of other forums where people reported having the same problem but on older engines. Their fix was replacing the gasket with a different style that had a thicker part of the gasket that went on the front. I checked Summit's website and sure as ****, they offered a gasket that included "thicker front" in the description. The gasket cost 10 bucks more and is grey instead of blue so it looked promising.

Summit part number-FEL-1886

After I got the old gasket out to compare to the new one it was barely even noticeably thicker as you can see.

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I measured the two with a caliper as I was very skeptical of this new gasket fixing the leak since they look pretty much similar. The caliper showed the new gasket as being barely bigger. I installed the new gasket and the leak has stopped. I wish I knew how to determine which engines need which gaskets or a cut off year or SOMETHING. I would say measure the grove in the bottom of the timing chain cover but cant think of an easy way to do it.

I am going to drive the truck around some more to make sure its not going to leak but so far so good, hope this helps someone!
 

Swims350

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wow weird pan and block.

you ever try and run the casting and sufix numbers to be sure exactly what it came from? I'd be interested to know and to know if they had the right gaskets for it then.
 

Irishman999

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305
wow weird pan and block.

you ever try and run the casting and sufix numbers to be sure exactly what it came from? I'd be interested to know and to know if they had the right gaskets for it then.

I looked for numbers on the back of the block where they should be and instead of a serial number I found "305". I will keep looking for the numbers on the block but I really dont care much about it anymore since this motor will end up replaced. I think its a 305 crate motor from somewhere that got swapped into a car that someone shortly after crashed, then it got swapped into my truck in 95 when my uncle had it.

I looked around online for a gasket that would work but had no luck.
 

Swims350

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none
the newer models the casting number is up higher on the bellhousing flange or on the other side top section, my 88 is on the PS top bellhousing area.

The suffix codes are still on the PS under the head area, where the alt. usually is, not actually under the head. The suffix will tell alot more, it pin points the exact year and such most times.
 

austinado16

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Thanks for the nice write up. I was pondering a pan change a while back in order to get a higher capacity pan, and maybe cast aluminum with fins. Held off because I found an industrial sized oil filter at NAPA, and it holds about a quart extra.
 

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