I'm reinstalling my oil pan with the Fel-Pro one piece gasket on my 79Z. Only thing is the motor is not the original for car and #'s are gone off block. I was told it is a 350. My ? is are there any differances in small oil pans in the front seal area, mainly the depth. The gasket I bought for the 350 oil pan doesn't fit the front seal area like I think it should, unless it compresses upon install.

I went through this with my 71SS. If you have part number OS34510T, this is the one piece gasket with the THICK front seal. If you need the thin front seal, then get part number OS34509T. My 71SS has the original motor and required the thin seal and I was given the thick seal originally at the autoparts store. Hope this help.

Thanks I'll try that.

same happened with me, but i think it was the new oil pan that i got (on my original 71 block) that required the later sized gasket... sounds like you might need the earlier model year gasket?