Lousy Brakes...What to do??

['70 C/10 SS500]

This is going to be a long one, so bear with me! Well, this weekend I got the exhaust done on my 500 Caddy motor swap project. For those of you following along, I went with my plan with a slight change: instead of a full 3" exhaust, I had 2 1/2" out of the manifolds for the head pipes, turning under the frame and outward toward the cab sides into 3" in/out Flowmaster 40 Delta Flows mounted directly under the cab floor (outward of the frame rails) with 3" pipes out of the mufflers turning a 45 deg. out to dump out the sides directly under the rear edge of the door. Truck sounds great, the exhaust shop did an excellent job!! With the exhaust done, I could finally run the motor more than a few seconds and a bit later I took her for her first drive in over 7 months. I had now completed my journey from I6-292 to V8-500 and with NO BRAKES!! Turns out that the front flexible rubber brake lines were shot and needed replacing, passenger one was leaking very bad. I replaced those yesterday night and at 3 O'clock in the morning was done bleading the brakes and ready to drive her to see if it was better. The truck now has brakes again, but not the best. After spending over 8 hours repairing (front) and bleeding all the brakes, and the thing still feels a bit on the mushy side. I have to plan for my braking and brake early. If I count out the idea that the lines still have air in them, what could the cause be for the weak brakes? Could it be the shoes themselves? Would worn out shoes lead to a mushy pedal till about half way depressed? What can I do to get a firmer, faster braking drum machine? I'm upset that all that time spent on repairing the brakes didn't lead to a stallion on the stoping! Give me some ideas please.