Doug, the reason that 3rd gear is the weak link, is because 3rd is the furthest gear from the rear mainshaft bearing. Under load, the gears are trying to push the mainshaft and cluster away from each other, 1rst & second are close to the large rear bearing in the case, and 4th is just the input locked to the mainshaft, and the front bearing for the input is less than an inch from the gear, so its pretty solid too. With 3rd at the very front on the mainshaft, when the shaft is spreading, the teeth on 3rd can ride up higher, rather than deep into the widest part of the gear teeth. On an old Nash 5 speed, there is a center bearing which helps hold everything in place, and on the G Force 101A, they have a "handcuff" that acts as a brace to prevent the mainshaft from walking away from the cluster. As for finding the correct input shaft, you never know who may have one laying around. I bought a bunch of stuff from a ex FE Super Stock racer on the East Coast a few months ago, and he said that he had a couple of Jerico input shafts left over from his 428 4 speed days. I got one of the inputs for DaleP, we were going to buy both, but he couldn`t find the 2nd input at that time. I could call him to see if he did eventually find it. He also told me that one of his old DR4s was for sale , may still be. The input I got for Dale is a Ford big spline 1 3/8"x10, but both of my Jericos use the MoPar "Hemi" spline, which is 1 3/16"x 18, but with the correct length and pilot diametr for a Ford. Actually, although both my Jericos use the same MoPar spline, the inputs shafts have different lengths, as the trans I use behind my small block Ford, uses a T5 depth scattershield, so its input shaft is about 1" longer than the trans I use behind my FE.The nice thing about the MoPar spline input, is that I was able to use much more common small input Ford throwout bearings and clutch forks, rather than the rarer 427,428,429 big input stuff, which gives a little more clearance inside a conventional depth FE scattershield. Also out here at least, most of my racing buddys tend to use the MoPar spline discs, so if ever needed, a replacement disc is easy to find. Years ago, we changed the main drive gears on the Jerico behind the FE, so I could use it behind my 85 Mustang 5.0 Stock Eliminator car, which changed first gear from 2.96 to 3.19. A couple of years later, I bought my 2nd Jerico, and was lucky in that it was already a T5 length MoPar spline with a 3.19 low, so other than the input shaft length, I could use either trans behind either engine.
