Memory compatibility ddr2 pc8000 with pc8500

I have a evga 780i ftw, with 4 gigs of 0cz pc 8000 SLI ram. I want to go with a 64 bit Win 7 OS. So I want to put 4 more gigs of memory. I found 4 gigs of pc 8500 ocz sli ram. Will these two pairs be compatible? Will I need to change some bios settings? here are the specs of both rams.

1000MHz DDR2
EPP 5-4-4-15*
(CAS-TRCD-TRP-TRAS)
Available in 2GB (2048MB) modules and 4GB (2x2048MB) D/C Kits
Unbuffered
SLI-Ready XTC Heatspreader**
Lifetime Warranty
2.1 Volts
240 Pin DIMM


# Cas Latency: 5
# Timing: 5-5-5-18
# Voltage: 2.2V
# Multi-channel Kit: Dual Channel Kit
# Heat Spreader: Yes
# Features: Platinum-Mirrored XTC Heatspreader 2.15V EVP
# Recommend Use: High Performance or Gaming Memory
# Parts: Lifetime limited
# Model #: OCZ2P10664GK
# Item #: N82E16820227298

Because I found a good deal on this memory. I will probably just keep looking for a good deal on some more pc8000. Someone on another site said 4 gigs is more than I would ever need, but with a 64 bit it seems like 8 gigs would be pretty good.