And if it makes a difference, this started right after i installed a performer intake.
I feel like i might not be able to give you much info on this because i dont even know WTF is going on.
So yesterday i get in the truck, fire it up. Starts right away. I go to a grociery store, come back out to leave and the truck won't start. It cranks very slowly. So i have my buddy jump me. No worky. My dad comes, we try to jump it again, even to the solenoid. Still cranks very slowly. We notice the battery cable is loose on the starter (the whole peg was loose) so we pull the cable, tighten the peg, put the cable back on and tighten. It now cranks fast!!! (Still no start, turns out there was a second problem being that the msd box's ground wire came loose).
We get it home, i fire it up this morning to bring it into the garage to adjust the timing, and it fires right up. Awesome, problem fixed.... NOT. Just now i went to start it again, and it is doing the VERY slow cranking thing again.
I don't think it is the battery, because i still have full power with headlights and my dads tahoe while running, jumping to my solenoid still did a slow crank.
I think it is either the battery cables or can it be the starter? We made the battery cables, the battery is in the bed. THe cables are welding ground cables, they are huge. We melted the ends onto the cables, maybe they came loose??
Need to fix this problem quick

can a starter be replaced without pulling hedman headers?