Need help with gear ratio

Hi everyone, my name is ravinder I’m from British Columbia,canada. I recently bought a peterbilt 579 with x15 500hp 1850 torque, 3.25 gear ratio,235 wheel base, meritor 2014x4dcrnn742 differentials,12 speed eaton endurant hd amt tranny, i used to do jet fuel for trimac as a company driver nd really liked it but then I decided to grow and wanted to be an owner op, as I’m new in heavy haul(tanker) industry I didn’t had that much knowledge about choosing the specs,so I got a good deal with my truck nd bought it, but unfortunately trimac said no to me cus it’s not heavy spec, now I have another opportunity from some company to do a local run for fuel superb’s but the problem is there’s 3 steep hills to climb on my way back from the refinery (i.e kamloops to Langley)nd I’m really confused if my truck with above mentioned specs can haul it? Or do i need to get the gear ratio and diffs changed?? If yes can someone please let me know what can be possible with my current setup? Hoping to hear back soon from you guys, and sorry if this is a dumb question any little help would be appreciated.

 

Hi good morning,u think it can pull ? If i use like the manual mode and be easy?

 

It’s almost full gross super b’s like around 60000 kgs

 

They are meritor 40’s…idk what’s a super 40