Just had a 4 inch lift installed in my 2006 Chevy Silverado. Mechanic is telling me it took 30+ hours. Does this sound correct? Especially when the parts manufacturer says it should only take 10 hours.

Did you have all the parts waiting for him to do the job ? I have heard of some garages charging "storage fees" while waiting for parts. Sounds like he's looking to hit the lottery and your the pay out bank. Honestly no it should not have taken that long at all, but your now in a position where "you need to pay, if you want to play". The only way you can hit him back is to have a bank check made out to his garage or make the check out to the business and not him personally.

Argue hes done a shityy job Aka steering wheels off center, bump steer issue, oversteer in corners, wtf.....?

It's looking like it may need to go to court. Never received a quote. Going to try and show up with the manufactures specs and a pile of other evidence and see if we can't play ball.

Yes, he is playing your for a SUCKER buddy... Especially If you are not satisfied with his work... pernally If a guy does a fantastic job & it took a while longer i'd have no problem, but what did he say when you brought the issues that you were unhappy with to his attention? you may only need to treaten him with taking legal action in order for him to make it right. Was thee any kind of satisfaction gaurantee?

sometimes with shady folks like that the ol' half up front, half later is the way to go. or write up a contract if he is acting strange. Then that trip to court (if need be) is NO Contest.