Piston area size help.

[49.5window]

I have a 1949 Chevy truck that I autocross. It has a custom built chassis a GM performance LSX-454, T-56 magnum, Ford 9" 3.73 gears. I'm upgrading my front brakes to 14" spec 37 slotted rotors and Wilwood Aero6 calipers. I have Tilton floor mounted 3 pedal assembly. The truck weighs 3787 55.6% front weight. I have ask wilwood 4 times about what caliper piston area either 4.04 or 5.40 to buy and every time I call I get a different answer. I don't want a lot of peadal travel, I have about 3" now and that's been very good for me so how will each of these piston areas affect my braking and pedal travel and how do I know which to buy? Also would you spend the extra money on the Thermlock piston? I'm running 315/30/18 Rivals front and rear. I have Forged dynalite 4 piston rears (3.0 piston area) with 12.88 dia. rotors. I'm starting new here with master cylinders and I have every size Tilton makes so I can try different options. Non boosted brake system only Hydraulic master cylinders.
Thanks,
Gary ary

[iadr]

I don't see how we can answer your question without the exact specs of the rear (caliper/rotor), .....and best to let us in on what M/C diam.
You mention the Tilton floor mount pedal, that *usually* means un-boosted, but a couple exceptions exist.