Unable to reach max RPMs under load

[Sea N Sun]

Hello

I have replace the block of my 2003 350 MAG MPI engine with a new 2010 5.7 GM block. I now have a new problem, it will only go up to 4400RPMs in gear. it will go max RPMs in neutral. I have used my old intake, injectors, assessories, sensors and exaust, any ideas as to why thisis happening?

Thank you
John

 

[erikgreen]

Re: Unable to reach max RPMs under load

Also since it's MPI the computer may need adjusting. Take it to someone with the tools to read the diagnostics and see what it says, should be an easy fix.

FYI I don't think WOT should be a whole lot more than 4400rpm on that engine..

Erik

 

[Sea N Sun]

Re: Unable to reach max RPMs under load

Yes it is a marine engine, my previous engine was able to go up to 5300RPMs and reach 42 plus miles per hour now I only get up to 4400 RPMS and about 39 miles per hour