you can be nice to the 5 speed and it'll last just that little bit longer with good oil and gentle smooth shifting, but for a 2nd hand car of that age you wouldn't know what the car had been thru with previous owners (not that i'm saying the previous owner thrashed it) but being old, its only a matter of time. My 2nd gear broke when i was driving normally 20 odd 30 km/h around a corner up hill. then a tooth came off. I'd be happier if it had broke while i was doing a run on the skid pan or something.

I mean if it holds then congrats, but you'd also want to be prepared if it does break. Last thing you want is to spend the money getting the vf34, and all the supporting mods then broke your gearbox after a few months and have no money to get it fix, having no car to use untill you can afford to have it replaced. Or even worst, if you have it replaced then it breaks again after a year, lol. just a thought.