Acording to some of my books a super 88 diesel was 56 hp on the pto . and if you have a hyd on it that will take some power away .and have you done any work to the engin . like pistons and rings . it would not hurt to have some one esl double check the timing .it took my  few days of ad.to get my 88 right .And on my 88  when it runs the best not all the marks are lined up . thry this put the crank on the fp mark .then the marked tooth under the timing windo on the pump should be one tooth off twards the rear of the tractor .that is how my 88 is and runs good . i hope this will help you .
Slim20