Calling all car techs!?

ok guys need a little help on these crossword problems. Its for extra credit for school and its all about cars. Ive gotten most of them just need a few more. Ok need an 8 letter word second letter "a" fourth letter "s" and last letter "t" for an item nicknamed a bump stick. A 8 letter word second letter "r" last letter "k" for a non-powered technicians vehicles. And a 6 letter word starting with "A" third letter "R" and second to last letter "i". Any help is appreciated thanks a ton!