Just a quick thought for fun.
Suppose some execs got together and had a solid commercial business case for heavy launch ASAP. ATK supplies well tested Shuttle four segment SRBs to mate with current Falcon 9 equipment. Two SRBs are mated with a Falcon 9 core and two strap on stretched tanks built with Falcon 9 tooling.
At launch the assembly weighs more than the Shuttle stack did and has lower acceleration than the traditional stack even with the Falcon 9 core thrust. At SRB burn out, the falcon 9 and two partly empty strap on tanks mass about 2.4 million pounds and are on a lofted trajectory to compensate for the less than 1 T/W ratio. From the 1,500 m/s or so velocity at separation, the mass ratio to orbit should be around 8. Considering the strap on tanks are dropped three or four minutes after SRB separation, mass in orbit should be on the order of 280,000 pounds.
Your 140 tons is in orbit. How much of it would be usable payload?