timing

[artcap9]

Hi I am new to this site, but have found some great threads. I need some help. I have a 1997 SR5 4runner, I just recently had a valve job done it and am ready to reinstall them. How do I make sure I don't put them be back in 180 degrees off. When I took them off I place it at Zero degrees with the marks on the camshaft lined up. but I am sure the cams are not still in the same position as when I removed them. Any help would greatly appreciated.

Thanks
ARTCAP9