You should be fine for 8 weeks. I think a lot of the problems or gossip you hear about tren are just that. Its not as harsh as many people think. Of course everyone is affected differently.
I was thinking about going 10 or evem 12 weeks, because i'm doing a 15 week cycle. The longest I've used tren is 8 weeks. I know there's someone out there who has used it longer, and I just want to know how it went.