I am putting my early 2000's (2003-2005?) Subaru sohc n/a 2.5 engine back together. The new timing belt I bought is a Gates T304. The belt I am replacing is a Gates T307. (I built the engine wit the T307) They both have 223 teeth and are the same width. Both seem to have the same shape profile. The search I have done show that they both work. Does anyone know if there is a difference?