[Coley]

Originally Posted by AirSpeed

I have no idea what gears, the trans shifts solid, was recently rebuilt and my old engine was easily three times more powerful. The truck was actually fast. Tires are new but the same size, 33", my old worn out engine had no problem spinning the tires. Not that I go around spinning my tires but it would do it without effort.

.......33" Tires, ok.
3/4 ton? 4wd?
....to my recollection the 290 hp engine was not a really great choice for these (heavy) trucks compared to the lower hp engine due to its poor low rpm torque. The lower hp engine actually produced more low end power and torque but often people buy/$$ the hp figure.
That soft power issue would be enhanced and really show up by running 33" tires.....they take a lot of low end torque to get going particularly when mated with the stock 3:07 gears.
It might be that your previous engine had a more suitable cam for a truck than that 290hp motor. There has been lots of discussion around this motor but I believe they (Summit/Jegs/etc) mention that this engine is not suitable for heavier vehicles...ie: trucks...but maybe more info is required on this.
C.