Long distance trips

[Yellowturtle]

I finally had my Suzuki Carry van F5, 550cc 5 speed change to a F6, 660cc 12 valve, 4 speed manual(carburator type) and I love the performance of the 12 valve. To bad a 4 speed transmission was not available and no turbo or EFI either. I already change my tires to 175/65, R13 a little offset so when it rains the side of my van gets dirty as soon it hits the wet road but I find my tire specs stable on cross wind and when huge bus or trucks pass by. I also install racing air filters and I am planning to test drive for road worthy and performance. Just want to inquire on the following questions:

1. Is the Suzuki carry van can survive a long distance trips and in
hill climbing especially if your going to encounter several steep
ones?

2. For those with F6 engine carry van, what is your top speed?

Anymore advise is very much welcome

Thanks!