Hi, 5.7 had a couple of spun rod bearings so I pulled the motor and put in a 5.7 out of a 1997 Tahoe. Has fuel pressure, has 12 volts to coil, has power to crank sensor. I'm not getting spark. I get a very weak spark out of the coil. (not enough to make it to the plug) Is there something I'm missing with either the computer or ignition? Do I need to flash the computer for some reason? Thanks for the help!