is there any point in turning up a 3406B..........

Depends on if your pyrometer probe is pre or post turbo. Wouldn't run it much hotter if it were pre.

 

First off, if your engine is stock and your getting up to 1000 on the pyro you got something wrong.

Id start by pressurizing the system and check for boost leaks.

After you you get a clean bill of health on your engine, then maybe think about turning it up.
They run great opened up and a turbo off a 550 e model./c-15.

 

I think u got that backwards. If it was pre at 1000 that's nothin. Now post , it's getting up there for a B cat. Any truck I've ever seen always has the probe post turbo. At least from the factory.

 

I agree a stock B has prob got a leak on the pressure side or timing issues if it is hitting a 1000. They always seem to pull better if you back up on the throttle and give them a little air when they just start to pull down a little

 

Not knowing if it's stock, if it seems to do fine I would leave it be. I keep the fuel turned to both mine. Course the standard hood truck is anything but stock. It rarely gets past 950. The exhd 359 is just turned up a little with a Borg Warner turbo and matched nozzles it will hit a 1000 if you stay in it. All that being said you are pulling mountains in that area. I'm pulling hills in this area. With me never having run that area it's hard to give a fair comparison

 

In my old trucks with mechanical engines 1500 was the lowest I would a long grade with. I was usually closer to 1700 or so. Like wore out said it seemed to be happiest in a gear where you could get out of the throttle and still accelerate if you needed to. Some people call this " running free" I did find that it seemed you could lug it and have high pyro temp or rev it and have higher water and oil temps. I chose the latter.