Working on my l98, just got the timing cover on, balancer is bolted on, rear main housing on, using the stock oil pan and a 1 pc gasket that ive used on my current motor, but now the oil pan wont fit all the way, its got a gap if i thread in one side the other side has a gap....

Stock oil pan
Mr gasket timing cover
felpro 1 pc gasket

Am i supposed to use an aftermarket pan if im using the aftermarket timing cover?

 

Depends on the timing cover.

Can't think of any particularly good reason TO use an aftermarket TC, and ALOT of good reasons NOT TO (this sort of thing being among them).

Sounds to me like your oil pan fits fine; it's the timing cover that fails.

What benefit do you expect to derive from this part that doesn't fit?

 

The benefit is using a cover that can go on the new motor without taking my current car down as its my dd. Are there different 1pc gaskets? As in an older style to fit in the timing cover? Its thin on the cover and ive used the felpro gasket before on my current motor, but this one is different, gray and has a thick lip on the front which is why the pan wont fit im guessin

 

I've seen people (and done it myself) trim the "corners" of a timing cover to make them fit easier with the pan gasket.

You could also go junk yard shopping for a factory cover. Sand blast it and powdercoat if you want it to look clean. I've heard chrome sheetmetals (pans and covers) like to leak also, never used any so idk for sure.

What's the timing tab like on the mr. Gasket cover?

 

Its an aftermarket tab matched with summits harmonic balancer, its accurate so its good enough for me lol Ive been doing some searching and it looks like autozone gave me the wrong gasket... I looked thru my old reciepts for the gasket thats on my 305 and they dont match up, I can either trim the gasket or get the right one, the one i have now is too big, and the timing cover it for an 87, dont feel like searching and spending extra money on a different cover, much easier to get the right gasket lol