Twin turbo plans
I think 10psi is under your components breaking point. But I would be a little suspect on your block. 650 is alot of HP for a stock block. With all the money you are spending, consider an X or R block. Copper gaskets are bulletproof if you can get them to seal, shouldn't be a prob with new AL heads, but be careful of the annealed portion of a used head where it has been compressed over the old head gasket fire ring, sometimes it has a depression there. A 6 speed with a turbo sounds like a lot of shifting. Turbos love to work against something, ie a low rear gear or a wide ratio gearbox. twins would help with the lag, but a properly sized single will work as well with less plumbing. And lastly, buy your injectors (and ECU capability, ie 3 BAR MAP) to the highest power level you think you'll achieve, now and in the future. Its pretty EZ to duty cycle down a large injector set for lower HP, but harder (if not impossible) to raise small injectors to new power gains without exceeding their D.C. ratings. Keep posting your progress.
Remember that Boosted Power is Linear and the "Shock Factor" is basically none. 650 HP on a stock block boosted will live for a very long time. There is a member here that built a 340 Twin Turbo with a stock crank & rods, W2 Heads that made 911HP to the tires and it never blew up. I truly believe that people under estimate how strong the mopar small block really is.
On mine I am anticipating 850Hp and over that TQ to the tires. I am using a 360 Block/410 CI with a Scat Forged 4" Crank, Falcon H Beam Rods and Wiesco Forged Eliptical Dish Pistons, Indy RHS/X Heads done by Brian at IMM Engines using Cometic Head Gaskets and ARP Head Studs. The machining was done with the use of the Cometic Gaskets in mind ahead of time, super smooth cut on both the block and the heads. I had Brian Line Hone the Mains with ARP Studs I also had him Line Hone the Cam Journals. I recommend doing this on ALL engines. Also using a Solid Roller Cam. I have build a few SBM now and this engine spins super easily, easier than any engine I have had to date,
BIG DIFFERENCE. I believe it has to do with the Cam Journals being Line Honed!! You can grab the crank with the pan off and spin it no problem at all. The key is
good machining and to keep the intake charge as cool as possible to avoid any chances of detonation. Detonation will Kill any engine quickly. Just my 02 cents....
Ohhh and you can get thickness from Cometic in any size you like. Call Don at 4secondsflat.com
Custom Cut Cometic head gaskets - Available thicknesses, .027", .030", .036", .040", .045", .051", .060", .066", .070", .075", .080", .086", .092", .098", .120", .140".