|I believe the 3800+ was also an 89w, so you should be fine. 65 is a little high, but if it doesn't get any hotter than that it'll be fine.|
Did you remember to clean the heatsink and use fresh thermal paste?
Super 939 | Dual-core Opteron 185 @ 3.2GHz | 4GB PC3200, CL2 | 1.0TB
2x GeForce 8800GTS in SLI | Blu-Ray | X-Fi Ti Pro PCI-E | W7 Ultimate x64