So this is my first post on the website but im gonna do my best. I have a 2001 lb7 that i bought off an older guy with 165k miles on it. Only mods are a 100hp tune and 4 inch straight pipe. Two nights ago i was giving it some gas maybe about 75% and gradually led onto the pedal when the truck wouldnt down shift thought it was alittle weird when suddenly it felt as tho it popped outta gear, pressed the break popped back into gear so i rolled to a red light and noticed the truck was stuck in what seemed to be 3rd gear and wouldnt go into any other gear including reverse. Shut the truck off than back on again and its still throwing a code but will shift. Got a quote for $4,100 on a brand new allison w all the upgrades from over the years. So the real question is bigger and better(what im leaning toward) or the new stock one. If i was to go bigger i would need some suggestions. Thank you