Hi relaxalot, I have read pretty much all your posts related to your howard 288, I have a 2015 with 600 sci that was a stage 3 that I just upgraded to stage 4 the stage 3 with a heavily labbed maximus 32 and bravo 30 labbed, after the upgrade to stage 4 same speed pretty much with both props, I did try a imco -1 drive no change, on your lower did you stick with the imco and is it the stock length?, TIA Robb