I doubt that Dub will know anything more than it is an equivalent to the existing TT.40 and EVO .46 with a 9x6 prop. On paper your engines should be faster. In Club 40 racing we use the World Models Skyraider 2 which has more drag but the same engines as 424. I have never been beat (in Club 40) by a .46 in the few times I have raced against them. Don't forget that Dub Jett engine is 3x the price.
Mixture doesn't change noticeably if using a Bubble free tank do you run those?
Sparky