Weiand upgrade to 500 hp 454's
 

Ok, its time to make some additional HP so here's the question. I have twin 1984 454 running GM 990 heads with extreme duty SS valves, .030 on the pistons, solid lifts; all forged stuff. Running TRS 425 outdrives with C-72 transmissions. Currently running Holley dual pump 750 with 88 squared on the jets. The cams are:

CompCams - Part # 11-000-5
Grind CB 6084 /6002 FT114
Intake Exhaust
- Valve Adj. .018 .020
- Gross Lift: .533 .562
- Duration @ .016 .268 .282
Open Close
Valve Timing@ .050: Int. 5*BTOC 45* ABOC
Exh. 56* BBDC 0* ATDC
Intake Exhaust
Duration at .050: 230 237
Lobe Lift: .3140 .3310
Lobe Separation: 114*

If I use Weiand Pro Street Supercharges (177 c.i.d.):

1. What carbs do I change to? Would Dual pump Holly 850's work?
2. Do I order the long nose or the short nose? (crossovers, no water pump)
3. What would the recommended jet size be?
4. Will the stock 90 gph mech. fuel pumps be ok?
5. How much boost can I run safely losing a ton of reliability and how do you control the boost? From what I read here, sounds like about 8 psi is nice and conservative.
6. What about recommended spark plug?

Not looking to go racing, just need a bit more speed, currently runs about 74 mph. Any advise would be greatly appreciated.