Terrax:
Class 75 Strenght without supplementing it in any way by additional cosmic energy.
Terrax possessed vast cosmic power granted him by Galactus. Terrax's body was coated with a flexible rock-like shell that was impervious to extremes of heat and cold, from 50 degrees above absolute zero to the interior of a small sun, pressure up to 100 Earth atmospheres, and concussive force up to a fall at terminal velocity from the limit of Earth's exosphere. His body had been sustained by cosmic energy, making it unnecessary for him to eat or breathe.
Terrax's mutant ability to psionically manipulate the molecules of rock and earth was augmented by Gaiactus's transformation at least a hundredfold. Terrax could move planetary masses up to 100 miles in diameter. He could move asteroids of 10 miles in diameter at speeds of up to thousands of miles per hour. He could control the direction of a swarm of meteors within 100 miles of his person. With concentration, he could affect a small piece of matter 1000 miles away from him. The farther the distance, however, the less mass he was able to affect. Standing on a planetary surface, he could affect tectonic plates sufficiently to cause earthquakes and create chasms in the surface thousands of feet deep or wide. Deploying his powers to the maximum extent, he could separate a landmass the size of Manhattan Island and levitate it miles off the Earth's surface. On worlds with lesser gravities, he could lift even greater masses.
Terrax, like all of Galactus's heralds, was able to enter warp-space and negotiate through it in order to cover great spatial distances. Traversing through the normal universe, he was able to attain .75 the speed of light.
Terrax wielded a cosmic axe which had several powers of its own. It was capable of emanating waves of destructive force sufficiently powerful to rent a tear in Galactus's own ship. It could also project highly impervious force shields. Since it operated independently of rock and earth, the axe augmented the scope of Terrax's power.
Captain Marvel:
Class Superman Strenght, around the 80-90% of that of the Man Of Steel
Class 100 Strenght in Marvel Universe
He can also charge his fists with magical lightning enhancing the strenght of his blows
Invulnerability of Superman's level
Flight at great speeds, considering that is speed is a gift that rend him fast as Mercury or near to him, he can be put on Supes level
Superhuman Speed and Reflexes, his reflexes are 20 times or more than the human norm.
Now, i haven't seen the strenght limit of Terrax, but if the Thing can withstand against him, Captain Marvel can beat down him with superior strenght.On the other hand the power cosmic grants to Terrax the ability to increase his base strenght, maybe into Class 100, but not at Marvel's level.The axe can damage the spaceship of Galactus, it means it's a weapon that can seriously give problems to Shazam, and mixed with the other powers of Terrax this could grant him the chance to keep Marvel busy and knockdown him with his strenght, but it depends of the strenght limit the former herald can reach