[Mackman]

Originally Posted by continental

:roll: :roll: :roll: SUUUre. I've got a 300 Mack with a 5 speed, and my
wagon grossed 96000 and pulled the Grapevine 70mph in 6th gear, noooooo problem.

He did say a MACK so i believe it. :lol:

[continental]

Well, first it was 475HP at 80000lbs, now it is 550 with 77000. In neither case
will you climb the grapevine doing 60MPH. And I speak from experience.Especially with a 3:55 rears.
Any other EXPERIENCED driver on this subject?

[Teal 95 KW]

If you would have caught the first 5 or so words of my original post. I said "well it says 475 ....." Bigger turbo, injectors, and computer work all tend to improve upon that. I'm supposing also you will doubt the fact that my single turbo pegs the 40lb. guage and keeps building boost too...OR the fact that it will spin to 2400rpm all day long...surely a stock 475 doesn't do that. :roll:

3k lbs. isn't going to make a difference in how fast/slow my truck pulls the hill. 60mph in 11th gear is about 1900 rpm in my truck.