I went overkill with a Rollmaster double. If it breaks, the whole engine is doomed anyway.
ATI Harmonic Balancer also helps - most of the time timing chains break due to bad harmonics.
And yes, interference.
__________________ 2002 Blk/Blk Trans Am WS6 A4
TEA Stg 2 LS6 Heads 62cc & LS3 Valves | EPS 234/242 111+3 | Johnson Short-Travel Lifters | Manton 11/32 Pushrods | Lunati Trunions | Cometic .040s | Synergy Oil Pump | Rollmaster Timing Set | ATI UD 10% | GM 42lbs & Racetronix Pump | NGK TR6/Firecore50 Wires | FAST LSXR 102/102 TB | FTP 104 Lid & TSP MAF | Kooks 1-7/8" Headers & 3" TDs | FLT Level 6 Trans | CircleD 2E 4000 | 3.5" DS | BeCool | BS Street Lites | Nitto NT05R | BMR/Koni/UMI | See my build list here