If I could just coin in on this little Kozzom0 and SgtPappy conversation. The Yak-3 in which you're both talking about that has a 708km/h speed is the post WW2 Yak-3 that was powered with the unreliable VK-107 or the Western name: M-107. ALL Yak-3s in WW2, were powered with the reliable VK-105PF-2 which put out about 650-655 km/h or so. The VK-107 engine that Klimov created came out too late for WW2, and was originally intended for the Yak-3U, but was put in afterwards which was later taken out because of its unreliability.
So keep to the WW2 Yak-3 which had a VK-105PF-2, not a VK-107.
Thought I'd correct that.
EDIT: Oh and I forgot to mention, there is no such thing in Soviet history or anywhere of the "VK-1097PF-2" engine. So wikipedia (incase you're interested at all) is wrong on calling it the VK-107PF-2. Specially when they're talking not about a Yak-3U or anything, but just the original Yak-3 (The basic simple one that I personally prefer) which had a real world Soviet VK-105PF-2. No where in my books on Yaks, is there a mention of a VK-107PF-2 engine or anything.