OK, well first question is: why are you asking about larger jets
My advice is to never “drill out any jets to a larger size”. This will only cause confusion for future repairs…In other words, some tech down the road might be trying to diagnose a rich condition at high speed…So, naturally, he will inspect the high speed jets to make sure they are correct…The tech will look at the jets, they are stamped 58D, which is the correct size, so he will move on looking for some other issue. But, in fact, the jets are not .058″, because you have drilled them out.
The next thing to realize is that the “C” and “D” stamped into these high speed jets is very important. This indicates the direction of fuel flow through the jet. So, a 58C high speed jet is not the same thing as a 58D high speed jet, even though the openings both measure .058″.
That being said, you will find a complete listing of all the jets and their part numbers in any late model OMC service manual.
And finally, like Frank says, please don’t put in larger high speed jets expecting the engine to run faster….
