If your Lil' Red Express has the original rear end in it, that should be a 9 1/4 and have 355's gears. I have a old 1978 Lil' Red Express that was my dads at one time and have owned a few of them over the years.. I had a extra Lil' Red 9 1/4 rear end and it's under a old 1937 Plymouth Truck right now.. ..