My 12v 1997 loses power after 2k and smokes/sputters blue smoke. Truck seems to idle good no smoke, and before 2k runs well, but the closer I get to 2k and the more power I need this loss happens.
Will be changing the fuel filter. But it might be related to a previous problem. the fuel solenoid went bad, and when priming and restarting, lots of white smoke and poping. I think maybe that blew the head gasket between cylinders. Is there a way to determine that? I figure fix the possible easy causes, then what's left is the head gasket.

No air leaks between turbo and intake.

Are there any specific symptoms of a blown head gasket between cylinders? Or easy tests?

The threads I have read about bad head gaskets between cylinders seems to fit my symptoms.

 

It could be a lazy overflow valve on the return line off the P-7100 pump.

Try LIGHTLY pinching the small section of rubber return line with some small vise grips or the like and try revving it up. If it suddenly runs better.
Order a new OFV and you should be good to go.