If they were mine,I'd probably give them some morning sun only for now.The leaves will most likely continue to burn because of the recent transplant,if left in full sun.Some shade is best in the hottest periods of the day.
It's getting a little late in the year to fertilize now.I use Hollytone or Jack's 21-7-7 or 20-20-20.Miracle-Gro will also work.Spring into early Summer is the time to apply.
Are they two different varieties?They should be for fruiting purposes.Six feet are pretty good size.They could flower next year,but still may not get fruit.They can be helped by transferring pollen manually from one flower to another.I use a small artist paintbrush or Q-tip.The flowers will be female first and then change to male.So hopefully,the trees will put out an abundance of them.Gather some pollen from each tree in separate containers and look inside the flower to find a ripe stigma,when green and sticky and dab some pollen there,from the different variety.It shouldn't take much.Bees won't do it.Flies and some beetles may,especially if there is some smelly meat around them.Also,it's best not to go overboard with a lot of fruit at first,as that may stress the trees.They are the largest native North American fruit.
Different kinds of grafts will work,like splice,whip and tongue,cleft or chip budding.
Some good info can be found on the Kentucky State University website. Brady

Here is a link that might be useful: KSU Pawpaw

Thanks bradybb. I hope they do flower next year. Now, where in the wild can I find paw paw trees?

Thanks bradybb. I hope they do flower next year. Now, where in the wild can I find paw paw trees?

"Now, where in the wild can I find paw paw trees?"
A lot of times they can be found growing by streams and using larger trees as a source of shade.
Here is a little map from Blossom Nursery. Brady

Here is a link that might be useful: Pawpaw Habitat