Kirk L-bracket on D800
The main difference between the D700 L-Bracket
and this D800 L-Bracket, http://www.kirkphoto.com/L-bracket_for_Nikon_D800.html
is where the screw attaches it the the camera tripod mount.
This L-Bracket can be adjusted further over, because of the screw slot, to allow more room for a larger body.
You would have to measure the bracket you already have, from the centre of the mounting screw to the inside edge where it curves up. Then one of us could compare that measurement to our D800, for you.
D800, AF-S NIKKOR 80-400mm f/4.5-5.6 G ED VR, B+W Clear MRC 77mm, AF-S NIKKOR 24-120mm f/4G ED VR, Sigma DG UV 77mm,
SB-910, WG-AS3, ME-1, Lexar Professional 600x 64GB SDXC UHS-I 90MB/s*, 400x 32GB SDHC UHS-l 60MB/s*
Vanguard ALTA PRO 263AT, GH-300T, SBH-250, SBH-100, PH-22,
Lowepro S&F Deluxe Technical Belt and Harness~Pouch 60 AW 50 AW & 10, S&F Toploader 70 AW, LC 11x26cm
FE, NIKKOR 2-20mm f/1.8, OPTEX UV 52mm, Viivitar Zoom 285,
Kodacolor VR 1000 CF 135-24 EXP DX 35mm, rePLAY XD 1080P