To confuse things further, it’s possible to creat a Yak-3 by converting a Yak-11 airframe (the -11 was based on the -3 airframe). For example, the examples owned by TFC and OFMC at Duxford a few years ago (and now sold abroad) were both Yak-11 conversions. This is also the route through which the radial-powered single seaters come (often referred to as Yak-3’s too)- convert to single seat and stick a Pratt & Whitney up front.