350 oil pan bolts don't line up..??

[parpart]

A friend of mine is putting a 1983 350 out of a G20 van into a 1971 Chevy to get it moving. The oil pan sump is crushed- so he has gotten 3 different passenger side dipstick pans for it.
The rear 2 bolt holes don't line up with any pan he's bought. Pan holes are too far to the outside of block. Block holes are "close" to the rear main. Any ideas? Thanks in advance.

[firebird77clone]

Easiest is to get a pan from the same model / make vehicle the engine came from.

[rspears]

I didn't keep track at the time, but wasn't there a change in the SBC blocks around 1986? Seems like there are several things that list '86 and newer when looking for parts on Gen 1 SBC's, like '58 to '79, then '80-'85, and '86 and newer. You might look for a '80 to '86 pan and see if the bolt holes line up better for your '83 engine. A good auto parts guy could probably tell you with a little bit of quick part number comparison, year by year, but finding a good one that's willing to try is a challenge.

Maybe one of the bowtie guys can give you the straight scoop on when GM changed their bolt pattern on the bottom rail.

[Henry Rifle]

This is where I would go, rather than trial and error. There was a unique pan for 1980-1985 SBC motors.

http://www.summitracing.com/parts/su...20?prefilter=1

[Scooting]

The change around the 80's was the change from a two piece rear seal to a one piece seal. Makes sense the pan might change.