1996 Merc 225 EFI To port or not to port (exhaust)

[Sam Smith]

I have a 1996 225 EFI Merc and have heard conflicting reports as to if I should drill holes (or have them drilled) into the exhaust. I have heard that there is too much back preasure and that is why they tend to load up at idle. I have also heard this will help with top end or maybe low end? By the way if it matters the power head is a 1997 while the rest of the motor is a 1996.



Thanks.