3/4" is what you need and you don't need to spend that amount of money on a kit that gives you options of either 3/4" and 5/8", just a longer length of 3/4" hose so it can take a nice smooth curve and a couple of clips (or just use the ones you already have). Buy a couple of feet of 3/4" hose and see how tight a bend you can get on it before it starts to kink.
Hey gang, I got a replacement hose for this after your feedback. Image attached.
I was wondering if this is a simple swap or if there are other steps I'll need to take if I try to change it myself. Removing and replacing clamps like these are about the extent of my mechanical ability 😬 Really don't want to mess anything up.
The first thing you want to check is whether the hose is a good fit with the metal piping in the P38. Second, due to the metal piping being in very close proximity to each other, you want to make sure that the hose doesn't develop a kink after install. I would've preferred the long hose route, as it is less likely to develop a kink and that the turn coolant makes is less abrupt. Third, you want to snugly and fully insert the hose ends to the metal piping. As for jubilee clips, I'm sure you've used one of these before. You want them tight enough that coolant doesn't leak out, yet not too tight that you don't damage the hose.