I've change the starter at the races with Hooker race headers in my old 1970 Hemi Cuda stick shift car, a real pain but I didn't have to remove the torsion bar or any of the steering linkage You can load test the battery by turning on the headlights first with a reflective panel in front of them or have someone watch the headlights and then hit the starter, if the headlights dim like real bad look at the batterey, if they don't dim it is probally the atarter Did you put a new mini starter in it? I've had cranking troubles in the race cars when hot with several different mini starters , it is slow to turn over on the first revolution and then the starter will spin the motor over properly, no problems when cold I think that problem is ground related I have to make sure but I really think it is ground related Two new battery in the trunk in parallel with the ground terminals hook together, engine block is grounded through the front and rear motor plates and one # 2 ground wire jumper accross the mid plate I did have one bad battery cut off switch give similar symptoms I would do a voltage drop check on the main battery lead to the starter before and after engaging it before deciding on what the real problem is, all stock 1969 Mopar cars had wiring issues, didn't they Lots of gremlins out there Good luck, let us know what you find