Rear toe in shims are included, They snap in place. The .025 inch shim is about 1/2 the thickness of the thinnest Associated Shim. I measure it with a dial caliper. Just select a washer with about half the thickness. By eye is OK.
Associated arm mount shim
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXRUU3&P=7
These are some .025 white nylon spacers
https://www.ssl-stormerhobbies.com/cgi-bin/seekpart.pl?src=ns&pn=ASC4187
at 80 F the Takeoff 27 would be good with stock or superstock motors. With powerful mods you will need the 32's
Use the manual or dowload a manual to see what shims to use for 2.5 degrees. There are a thick med and thin shim. Then add the extra thin shim.