454 running rough - vibration - new crank pump?

[Blackfin27]

Had a new Johnson sea water pump installed. My next trip the engine seemed to lag and could feel some vibration. Throttling up seems to increase the vibration.
Engine is not 'smooth' at 3250 the typical cruise she likes. My first thought was a bad plug, needs a tune up, haven't done that yet. I'm wondering however since the lagging and vibration seems to coincide with the pump job, is there a chance the mechanic didn't get it on right? I assumed the pump just bolts on, same pump was taken off and new same model installed with new bolts. Temps are good and I don't see any wobble or vibration on the pump...

Im looking for some guidance, the vibration and lack of power are similar to symptoms on another engine which had a bad plug and was missing.

Is swapping the new crank pump as simple as bolting back on, or is there an alignment issue here throwing off the harmonic balancer?

Thoughts? Next steps? Thanks.

 

[makomark]

I'd say the two items are unrelated...at least to the lagging..

If the engines are of opposite rotation, the pumps won't interchange without accommodating that fact...

as long as the pump flange mates up with the crank pulley, its a pretty straight forward installation.

If you know its time for a tuneup, I'd start there...

 

[Blackfin27]

I'd say the two items are unrelated...at least to the lagging..

If the engines are of opposite rotation, the pumps won't interchange without accommodating that fact...

as long as the pump flange mates up with the crank pulley, its a pretty straight forward installation.

If you know its time for a tuneup, I'd start there...

Thanks, that was my take also, but, had a 'new to me' mechanic do the pump. Moving on to plugs, wire, dist cap and rotor hoping this gets it.
This is a 2001 Vortec engine that has been very reliable, but last owner doesn't have records.