Thats because the motors and axles sit in different locations between the 3rd gens and 1st gens. You need an oil pan that will clear it. Took me a long while to find the perfect one for our mighty max's. 2003-2006 3.5L Kia Sorento Oil pan and pickup assembly. You're welcome.

https://www.ebay.com/itm/Oil-Pan-KIA...~w8:rk:47:pf:0

And yes, you should have got a v6 Max to start off. Just wait until you get to electrical.