I always like a 142.5 for the mag high. I never opened up the high needles quite so far though. Make sure you have a good tach. Pin it just long enough to get a top rpm then crack the high needles another 1/4 open. If rpm goes up then you were lean. Do that until rpm goes down. It's good to give back 50 or so rpm to stay on the rich side of peek rpm. Do this and you can enjoy guilt free WOT bursts. Those are great pipes.
I was gonna say something about the BRM's but I didn't want to be negative. Those beautiful billet carbs have drawn many of us in but nobody sticks with them hehe.