200 shot is good for a mech. pump-no need to go crazy...yet. Liek it was said, you will want more-nitrous is like sex with a hot woman, a little is never enough. I built a 406 for use with a 750 shot Titan plate system and I welded a sump onto a new gas tank and ran two -10AN fittings to (2) Edelbrock pumps with internal bypasses. Then I switched from the braided just before the pumps to 1/2" aluminum line for both lines up to a firewall bulkhead bracket I made where the lines went into separate regulators, one for the motor, the other for the fuel solenoids. Reason being is that the motor is dialed in @ 8 psi while the fuel solenoid needs to be @ 10.5-11 if I go max on the jetting (#122's) and go for broke with the 750 shot. I keep them separate more for fine tuning....I'm gauge crazy though-I gotta see what every little thing is doing and why. I don't like the idea of one supply line operating two different regulation levels...doesn't make sense to me and once you get into high lvels of nitrous, it's usually suggested to run a dedicated system just for it...my guess it's to narrow down any small delivery problems so you discern whether it's lack of engine fuel or solenoid fuel if you happen to be running rich or lean on either end-again, fine tuning. Oh yeah, I have a 100 micron filter on the primary fuel line and a 10 micron filter on the secondary (solenoid) supply line...Aeromotive stuff. The trouble with used solenoids is you never know what kind of shape they are in-hopefully they haven't been run much and haven't had crap getting stuck inside of them. Outside of the bottle, used nitrous stuff imo is not a good idea to play with-just a headache waiting to happen.