k i got a itr transmission and it grinds in third gear.. alot of people told me about the GM syncromesh and thats what im planning on getting.. but someone told me i have to mix it with something else? and how many quarts will i need?

also it is kind of hard for me to get in first gear now and im thinkin its the short shifter. personally i dont like the short shifter and i wanna change it back to normal.. wat all would i need?