Is there any difference between a thirdgen sump and any old aftermarket sump that you can purchase from any auto parts place?

Thanks.

 

Do you mean cosmetically, fitment, or performance wise?

As long as it is actually for the correct application Id think no for the first two. Performance has alot to do with the brand and sadly the price of said aftermarket pump.

 

I was thinking fitment wise. I can't see a problem but I thought I'd ask.

 

I think you should be fine

 

I notice that some places sell sumps for 55 - 79 and 87 up. Do things like rear main seal and dipstick position make a difference in the sump?

 

I think there is an issue with some aftermarket sumps not clearing the k-member, from what I recall from my browsings here. Seem to remember reading about members here having to notch sumps or k-members for fit.Try searching it.

 

Actually I think that is what I was thinking of. I vaguely remember something about this which is why I asked.

 

The oil pan for a non 3rd gen application will most likely make contactr with the k-member. Not all but most.
There is also hard contact with the inner tie-rod ends when the steering is turned lock to lock. You'll notice that a 3rd gen pan has pronounced directly adjacent to the steering linkage.
This is a note from experience as I was going to swap in a fresh "generic" pan that had been given to me only to find it wasn't going to work.