C1 1958 Oil Pan Gasket

[Al C.]

I've been searching the archives and the web to choose the proper (not necesarily "correct"!) and best gasket for the oil pan on this 1958 245hp engine. It appears that Fel-Pro makes an 1885, 34509, 34510 (all one-piece?). On-line photos show big differences in shape and location of large holes. Which is the proper fit for my engine, and best source? Thanks, ... Al '58 245hp

[Joe L.]

Re: C1 1958 Oil Pan Gasket

Al-----

If you have an original oil pan, use the Fel-Pro OS 34509T (one piece). If you have a replacement GM #359937 oil pan, then use the OS-34510T.

[Al C.]

Re: C1 1958 Oil Pan Gasket

Joe - Is it possible to tell which pan I have before pulling it? I'd hate to leave the engine works exposed to blowing dust for more than the pull-amd-replace time. The photos on the web show NO large holes on the 34509 versus 2 large holes on the 34510 - does that seem right? If so mine must be the original (thus 34509).
Thanks, ...Al

[John H.]

Re: C1 1958 Oil Pan Gasket

Al -

I don't know any convenient way to tell which one it is with the pan installed on an assembled engine. Once you drop it, flip it upside-down on a flat surface (no gaskets) and measure from the flat surface up to the 12 o'clock position on the front radius; if it measures 2-1/4", it's the original style that takes the "thin" (0.22") seal and #34509 gasket. If it's 2-3/8", it's the '75-up replacement style that takes the "thick" (0.41") seal and #34510 gasket.