I want to open a Mexican Taqueria in CA.I want to know if it is allow to use the Trompo to cook Tacos al Pasto

I've seen a few Mexican restaurants in California that used that gyro-type spit. I don't know why you wouldn't be allowed to do this. Some areas have either a government office that works with new businesses to help them through the licensing process (making sure all your cooking equipment meets fire codes, etc.) or else the Chamber of Commerce, which is a private group of business owners that you might want to join, might be able to help you with the licensing process and making sure whatever equipment you've got is up to code. Try calling the Chamber of Commerce and/or call City Hall for help in finding out what you need to do, or if you live in an unincorporated county area, call the county government office for help in finding out what's their licensing process and how do you find out what kitchen equipment will meet code requirements. I'm sure you can find some kind of upright spit that will work. Yum, that recipe sounds good.