Ok so you are going that far, you should really also replace the whole timing chains to the 2002 version. I did it on my 2001 that had 99k on it, and it was the SECOND SET THAT HAD BEEN DONE!
Bad design prior to May of 2001 build - which I see by the pics it is. What you will need to do is get all new sprockets, the full chain set from cristopher's and then you might as well since you have the engine out, get the 2002 bottom oil pan set up and then put in the 2002 oil pump which has the nozzles.
Now as it goes, I have the pump and pick up new in box if you want them. I was hoping I could swap that out when my mechanic did mine (2002 system now sans new pump), but when it was apart we found out the bottom pans had to be changed too.
The reason the you think the oil issue exists might very well be the original design oil system sucked and thus the in line change in 2001. I missed it by 2 months, mine was built in march 2001.