I just purchased some new wheels. The rears came out great but the front is not right. The specs are 8" wide wheel with a offset of 40. i plan on lowering the car and would like to have no issues with rubbing. What size spacer should I run. The rears are 9.5" with 40 offset also. Thanks for the help. I tried to search but had no luck.

you won't have any problem with spacers up to 10mm. also depends on what tires size your are running.