How warm do you run?

[Fishnut]

not to hijack the thread, but in saltwater I change the impeller every year or 100 hours. I think guys in fresh water would benefit from changing them too. I was amazed at the wear in such a sort time. the rubber was clearly memoried and had nicks from sucking up sea shell pieces.

 

[300 Ray]

Scorpio, I have an 86 300 with 5.7 IB's. Both of my engines run 150 right on the mark, at idle or at cruise. I would get a hold of a infrared heat gun (not that expensive) and see if there is much of a difference between ur manifolds. If theyare consistent with eachother then compare to other engine. If u dont have a blockage issue within exhaust I would be re-inspecting ur impeller and impeller housing. Dan