...IF you do swap - minimum you'll need the shifter rods and shifter relay ball for 5spd. And if there is a diff engine mount application - probably that too.Sometimes the shiftplate/shiftbox that bolts into floor can cause interference going into 5th cleanly - is what GB is talking about. But the 4spd shifter 'can' be modified if that problem presents itself. I had to modify mine. But would likely have a problem if i wanted to run the factory underbody shiftboot due to the mod....
i haven't done the governor mod...think that really helps at higher rpm so i wonder if that kicks in better with the 5 speed but 3rd gear in a 4 speed might work pretty well with the gov mod to (i need to do that).The 4A looks like it is ratio-ed about the same as the GP anyways
...5 speed ACH swap. There is some 5th gear interfence. So to go into 5th gear, I push down before going over an up.
Well, I just looked under my 1981 vw, it has a GP code transmission. Here is something interesting, my 1984 1.6N/A, bored .020 over with governor mod, lightened flywheel, 4A transmission, with p195 60 R14 tires pulls hard through gears up to 60-65mph. My stock 1981 vw 1.6N/A with GP transmission and p175 70 R13 tires is really slow to 60mph, but has a higher top end then my 1984. My 1981 can go to 80-83mph, my 1984 seems to barely top out at 73-75mph.