new build need advice

I have been wanting to build a smoker for a while now and recently aquired a pipe just to do the trick. I am a welder by trade and can make almost anything. I just want to do it right and I want some input. so here's my plan: reverse flow design big enough for half a hog yet can cook anything

42" diameter .313 pipe 60" long for smoking chamber i have enough pipe left for about 30" firebox or could go square with plate. any ideas and it seems the transition would nearly be wide open to allow enough air flow to enter the smoke chamber. I am drawing it up in solidworks as to design many times and cut once. let me know what you think

thanks in advanced

Good Luck

thanks for the comments I cant wait to start the flaming hatchet and go to work