98 K1500 engine power loss/sluggish acceleration

i recently just put a new 350 crate motor in my 98 k1500.
Once installed everything obviously was running well. I
have been driving it back and forth to work. There has
been a series of rain lately and the road I take to work has
been flooded. The water literally goes up to about the
door handles on my truck. After I took my truck through
the enormous pond like puddle, I took it home after work
to wash it off, and I let it sit for a week or so. When I drive
it now it seems to be sluggish when trying to accelerate. I
doubt it has anything to do with spark plugs or anything
inside the motor because I just had the motor recently
installed. Also I have new fuel injectors in it as well. I'm
just hoping I just didn't make a huge mistake by taking the
truck through that kind of environment. Any ideas? Please
help! Thank you