Is a 1" spacer (and 4" stud kit) needed with histeer/crossover arms for the tie-rod to clear the leaf springs on a k5 w/ d44?

It is if you plan on using the stock tierod with those goose-neck style tierod ends.. and I don't recomend them at all.
If you use tierod ends that are straight then you won't need a spacer.
The amount of force put on the arms, using a spacer of any kind is a really not a good idea to do. IMHO.
I wound up using the same tierod ends for my tierod that chevy uses on the stock steering draglink that you will be taking off for the cross-over set up.

Hope this helps....

I agree with HomeBuilt, spacing the arms off the knuckle will equal some bad news.

Why not use a 7/8" heim and space it there?

it is your truck, go look at it and see if you will need a spacer

depends on what springs you use
depends on what arms you use
depends on how much you have moved the axle forward

www.partsmikeparts.com

He makes a great arm called the "Super Arm." It is 1.5" and still uses the stuck length studs. It may work for you, it's really hard to tell though. You'll have to see where everything puts you as far as the set up goes.