Nope, no choke with that cam. I've got 706 heads on my 6.0 towing build. 2" intakes put in and bowls blended, and the chambers unshrouded for the larger valves. I'm running a Vinci 210/218. Stock 3.73 gears, stock converter, long tube headers. If the truck was newer or I was planning on keeping it longer I'd do 4.56 gears but as-is, it pulls very very well. The compression bump is the main factor below 3000 revs in my opinion, but mine pulls strong right to my 5800 rpm shift points. 243s are likely better, but I got my heads for $25 so that's what I used.

 

That's good news.

I figure worst case scenario where I totally hate it, I can put my 317's back on if things don't go smoothly. It's not like the heads are super hard to get at.

Will probably keep my eyes open for some 241/799's anyway, but I'll keep these on the shelf if something doesn't turn up soon.

Would you consider running them with the factory sized valves?

 

I didn't. And wouldn't.

 

Sounds about like my build.
Still in the works though.
Got the block out yesterday and hits the machine shop tomorrow.

I email Cir D and the response I got was basically using a stock converter but with 2A stall speed and some internal upgrades.
My truck is a 6500# Hummer H2 on 37's.
Once I get the motor done Ill be putting in gears.

 

Any progress? My 2500 wants 218 cam/ 243 head combo.

 

Howd it turn out?