What freeway are you talking about?

I know of chiraco summit heading to the river and the hills on the 15 near rainbow scales but never heard of Jacumba...

 

Seriously if you come to any conclusion other than working with your 8.1L, I'd just sell it and get another truck. By the time you put a Lq9 or Lq4 in your truck you could have probably sold your truck, taken that money and gotten a different 6.0 Suburban for a lot less time and money

 

I have to agree with this. Remember though, a suburban weighs a ton more than your old silvy did, and the silvy had the benefit of higher compression along with those 4.10 gears.

I would assume a low boost 6.0 would do the trick, but I can't really speak to how it would do under constant load in that heat.

This sounds silly... but if its heat soak that truly kills the 8.1 I wonder if the addition of a cowl hood would help out.

Outside of that long uphill, how does the 8.1 feel pulling this boat compared to the SSS?