Kerscher Balljoints from
www.kerschertuning.de will fit the pre-'85.5 944 spindles to late 1303 ('73.5 and later) control arms.
Go to
www.toplineparts.com and get the tie-rod flip kit. These bushings need to be installed in the spindle's tie-rod end holes, so the tie rod ends can go into the hole from the top, like a Bug, instead of the bottom, like a Porsche.
You will also need their tapered sport springs, or their Maxx Struts if you intend to use some wide, high offset 17" wheels.
If you don't use the Maxx Struts, then use 1303 front struts. Again, '73.5 and later with the two horizontal bolt holes. It's almost a bolt-on fit.
There's a search function at the top of the page that can help you find much info on this conversion.