I have a 1986 crew cab short bed with the following modifications. It’s a 350 I put summit vortex heads on it with scorpion 1.5 roller rockers, retrofitted comp cams roller lifters, a crane roller cam .488 intake & .509 exhaust, edelbrock 2116 intake, edelbrock 1406 carb, a huggers GM5Xtm torque converter on a th400, with a 4:10 rear end. MSD coil, MSD box, MSD wires. My truck starts up and runs fine but if I punch it from a dead stop it won’t spin the tire, posi is my next add on. Once it’s rolling around 40mph it will run strong when I floor it. But it’s a dog below that. Any suggestions?