Carburetor size Question

AJ/FormS said
I see a picture of alloy heads; are those going on?
At 9.75 Scr?

Thanks for the reply.

Yes, those are the Speedmaster heads. The builder has blended the bowls and done some other work. I asked today to remind me of the CR. I thought he had said 9.5:1 before but he said it will come in closer to 9.75.

I was planning on running a 275 or 255/60-15, 28" and 27.1 respectively.

My drives in this truck are going to be in mountainous terrain/ canyons, rolling hills, and a fair amount of interstate. I live out in the sticks and I can drive 15 minutes to get to the interstate (70-75 mph or 112-120 kph) or go the scenic route to the big city which is avg. about 45-55 mph (72-88 kph). It's 45 minutes interstate or about an hour taking the scenic route to get to the city if I'm hauling ***.

I'm looking for performance in that type of driving rather than from a stop.

Would you recommend going with a 3.55 gear with that tall of a tire? I leaning toward those tire choices because I have 15x8's and I want to fill the wheel well as much as I can on the truck.

Looking at Spicer Engine RPM Calculator
it looks like I might want to go witht the 3.55.