Help! Turbo pro drag race clutching!!!

What elevation and what is your weight?

I would go with strait 54. This would usually give you a little slow spool up which can be good for traction off the line but if you got notched primary weight your revs are gonna come up before shifting starts so should still spool quick. Prob is im not sure which secodary spring to start with.
Also if you havent already you will need to drill out the front track suspension arm top bolt hole and move it up that 1 inch, plus set your rear track spring a little stiff. Or your gonna damn near flip over at 18-20psi with a 155 and stock suspenson.

No contradictions to what's been posted already but Polaris red almond front spring should be considered as well as primary clutch belt spacing. I like smooth engagement so I tuck the heel of the weight under, leave the shift profile, and pull spider shims to get belt clearance to 20 thousandths or so. This must be done with steep helix and soft secondary spring to minimize over rev on launch. Remember you want 200-300 rpm of shift up after initial launch phase to match peak power shift as pipe heats. Also remember that more belt clearance equals more leverage of the weight once sheave contacts belt, equals faster up shift. Less belt clearance equals less leverage of weight and slight delay of up shift that can allow smooth launch and rapid turbo spooling/rpm climb.

Other approach that works with more effort is to notch the weight and "hold" engagement. Guys have to run 50-60 thousandths of belt clearance and often a loose belt with this set up to allow fast up shift of clutches once engagement notch hold breaks, to avoid over rev. I don't like this approach because launch consistency isn't great--but when a hard launch on boost is dialed in with good traction it's really tough to beat and it generally wins.

Guys will sometimes run horizontal scratches in spider towers at engagement point to further escalate engagement rpm without altering other shift characteristics. 60 grit wet dry is used to make the button stick a little at that point.

Last tip is if you don't care about engine beyond the race is to pull the deto sensor from cylinder head and zip tie it to anything nearby and handy. The Polaris deto sensor cuts power before peak power is made with mild deto. Some guys will insulate it with plastic washers to tune its sensitivity but if you're going for max power and have little test equipment pull it and go old school. Run great fuel, as much of it as your spark can hold and boost it to the sky.

Good luck