Yes this is the Polar Lights kit, and you are correct that the decals say it has the 429, but I decaled the body then found that the 429 did not fit, so it has the 427 in it.
If you are going to build this with the 429, you will have to relocate and/or fabricate the shock mount bars, so the 429 will fit. This was one of those "should have tested fit" type cars. But other than that, make sure the front of the car slopes down. Some of these Polar Lights cars had some issues from the cowl forward that the nose was up from the stock position, but some hot water and bending"ever so easily" got the nose of the car down.
Thank-you all for the kind words also