I've read a ton of posts on this, but still haven't found what I'm looking for.. does anyone have the specs for a stock '89 454 mag cam? The manual has lift, but no duration, centerline, etc. Also, what roller cams have people had luck with? I'm hoping to maintain close to stock performance, and not have to change valve springs.

The stock cam was a Crane Cam, flat tappet design i believe. I have just changed to a Crane 168731 Hy-roller that along w/ Iron Eagle heads allowed me to pull almost 500 hp on my .060 over 400 HP mercs.

Wannabe

Call "RMBuilder"/Bob Madara of Marine Kinetics in N.Y....he is the cam expert and can dial you in on whatever you're looking for. 585-654-8583

You'll have to change the springs to go with almost any cam change. Those springs are pretty wimpy and don't have the capacity for high lifts.

The cam for the 454mag/365 hp is .510/.510, 220/220 duration.

Yes he is and yes he can !!!

The good thing is the 365HP really wakes up from a cam and exhaust upgrade. Dont bother swapping cams unless you have some decent exhaust.

If I were going to upgrade a 454 mag, I would

install good exhaust,
roller cam upgrade
roller rockers
switch to a holley 4150 800CFM
good intake

You can put in a flat tappet cam from an early generration 502 carbed engine and leave everything else alone and wake it up a little.

That way you can still use the old srings and exhaust.

He is the GURU

call ultradyne and talk to Tim golsbe he's the man they did all the cam engineering in the 80's for mercruiser big block and small block chevys

Ultradyne Bullet Racing Cams at (662)893-5670