Had my 496 Mags converted to HOs. Cam swap and ECM reflash. Cheapest 100 HP I ever bought! Plus, they are completely STOCK!

Bob Llyod do the work? Stock flash or Whipple Stage 1 flash?

The Dana exhaust made a huge difference in my 26 velocity, great bottom end and HUGE mid range gains. Only 1 MPH on top but the whole shot is there every time. Got my set used and had a small leak sent the riser to Mr. Dana and he fixed it for free. He was very interested in how his product performed and worked. Not just a sell and forget company.

Lab prop 25 Hydro = 3 MPH

Dana exhaust = 1 mph

Thinking a re-flash is next as a 525 is not in my budget :(

Waters linger, your PM Inbox is full... Tried to reply to your last message but can't until you empty it out. Email me [email protected]

What mph does it run now?

GPS 73 with a light fuel load and two people. The 4 batteries for the big stereo i am sure does not help.


Last time out ran the V hard for a 8 miles and the guardian kicked in and took me back to idle. Ran the codes and the exhaust manifold sensor was reading hot. Talked with Dana Marine and was informed that they seen this problem with the later 496's. Considering my ECM was re-flashed by Mercury to the most recent tune to help with the dirty transom. I need the fuel pressure regulator to richen the motor back up.

With more fuel hope to see some more toped.

Waterslinger what rpm you turning at 73mph?