Okay so bare with me here. I have a k2500 with a mpfi 454 and I'm wanting to Turbo it. I've been really obsessed with a sequential setup where there's a small and a bug turbo and the small turbo turns off when the big turbo comes on. The whole engine will be getting rebuilt with forged internals and running on corn with a mega squirt ecu. I've already picked out the small turbo which is a borgwarner s400sx-e 72mm and I'm trying to pick out a big one, anyone have any ideas? Also, I'm trying to possible find a better way to control them. As of now I found some vacuum actuated exhaust cut outs that I'll be using with some boost controllers to control them. I plan on revving it from 6500-7000rpm with the first turbo steaming out at about 4500-5000 rpm at 17 pounds based on my calculations and the borg warner match bot