I have a few thread links for you to read through. Some are my own when I once contemplated doing the same exact thing.

Read hookin78's replies in this one;

'97 460 SD-EFI + D0VE heads? - 460 Ford Forum

I strongly believe that making an adapter or opening up the ports too much to try to match them, messes up the quench and airflow dynamics too much.

Here's a few more;
https://www.ford-trucks.com/forums/1...0ve-heads.html

https://www.ford-trucks.com/forums/6...onversion.html

If you plan on pulling your heads anyway, just port those F3TE's, maybe deck the block a little for a compression bump. At your elevation, I wouldn't go too high with the compression unless you are willing to do a MAF conversion, and possibly run higher octane gas.

I'm not sold on the idea of you needing a high volume pump. Elevation may affect the pump behavior, but I know I've never had problems with a stock pump @ 50-2500 ft. Easier?... running a synthetic blend 10-30 should give you a few hundred thousand miles if you change it every 3-5k.