My truck wants to start but wont. i've ruled out the battery and he fuel filter as being the issues. i'm buying a new battery. the parts store has always sond me batteries that are too small for the space but seem to work. the one i almost bought was small but the biggest thing they had with 770 cranking amps. someone else recommended i get a bigger one a 30h with 1025 cranking amps. another person said he would sell me a used semi battery cheap but it doesnt have posts so we would sauter new connectors. even with a battery in there though the truck tirns over but wont catch. could this be the glow plugs or the injectors? what should I consider first?