Where are you getting specs showing a positive toe for street use? Street should be -1/8 toe in front and 0 to -1/8 rear. I use the Ray Scruggs specs and have always been very happy with how my '86 steers and handles (except I use a tire pressure of 32 front and 36 rear). Here are his alignment specs and a link to his manual:
Ray’s suggested 911 specs:
Street Competition
Height Front fender lip: (Height varies for
24.5 to 25.5” suspension and
Rocker trim: wheel heights)
½ to 1” lower in
front than rear
Front Camber 0 to –0.5’ -1.5 to –2.25’
Rear Camber -0.5 to –1’ -2 to –3’
(Varies due to rim
width and tire
stiffness)
Castor middle of range forward – wide tires
middle – narrow tires
Front Toe -1/8” +1/16 to +1/8”
Rear Toe 0 to –1/8” 0 to –1/8” (use toe-in
if too much power-on
oversteer)
http://raystrax.com/ha/PDFs/HOME%20ALIGNMENT%20OF%20PORSCHE%20911.pdf