A generic (sort of) Cummins Big Cam question

290s had a turbo.
I also had a 1973 white road commander and it had a 335 cummins with a turbo also.
My 1974 pete 359 with the 350 had the compression release and a hot box on it.
In 20 below zero you could run the hot box for an hour and then pull the compression release and spin it over and it would fire right up.
The only scary thing used to be is it took about 15 seconds to see oil pressure.
The hot box warmed the coolant but not the oil in the oil pan.

 

There was a rule in my youth that you did not rev engine until you saw oil pressure. That took a while. Otherwise the turbo starved.

I have a issue with memory so forgive me if Im off in anyway, these modern engines sure took much of what was once long ago...

 

Your 290 can be uprated to 350 easily. The small cam 400 would require retiming. This requires the air compressor to be removed and the cam follower gaskets to be changed. When the front two cylinders are set at your chosen degree the center pair and rear pair must be matched within 2 degrees per Cummins spec. If you take care, you can easily get the variation less than one degree. The result is a smoother ruining engine. If my memory is correct, the timing fr small cam 400 is 40 degrees. You may have to resort to an offset key in the timing gear to get it that far advanced. A pulse exhaust manifold and dual entry turbo will help along with recalibrating the fuel pump.
Look at the water pump belt. Is a serpintine belt adjusted by raising an idler pulley or this model would have a pair of matched v belts.) Idler pulley would indicate FFC small cam (Full Flow Cooling)block. The small cam engines will not have much torque below 1700 rpm. The big cam was designed to have torque at 1300 rpm. I have experience with Cummins engines that have pushrod injectors. None with electronic fuel injection.

 

A hot box was an aftermarket auxiliary engine heater.
Mine was made by south wind.
It is basically a little furnace burner that heats engine coolant to about 150 degrees so the engine will start in cold weather.
Believe it or not it had a small fuel tank on it and ran on gasoline .

 

When you used the hot box and the compression release the engine would start quickly in 25 below zero weather but it took some time to build oil pressure because that - 25 degree oil in the oil pan was so thick.
In normal weather oil pressure would build quickly.

 

This probably dates me, but I remember compression releases weren't hooked up to a cable, and it was kind of a 2 man operation. One person spun the starter, another held the handle. And I disagree, if it's cold, and not 31 degrees for you mid-south folks, like below 0, or even 10 above, ain't nothing deader than a cold Cummins, and that compression release didn't give you much time. Best to get out the "torpedo" heater. Ah, the good ol' days.