ok fellas some time ago i put up a thread looking for some cam info but since that time i have changed up my program a bit. The motors in my ScarabIII are virgin, well kept, 365hp Merc Mags (454's and roughly 320 hrs on them) that i have put back in the boat for the remainder of the season after running them on the test stand and assessing they are in fantastic shape. Plan is to pull them out again this winter for a full rebuild, i was originally just going to upgrade the intake and cams and just run 'em. After rounding up some more parts i figured what the heck. Currently i have Edlebrock Airgap intakes (oval port intake matched to my rectangle port heads), CMI E tops, Crane gold 1.70 roller rockers. The cams i had originally purchased are Crane PowerMax #134242 H-286-2 and i fear they my be to small for what i'd like to get out of these motors now (would like to see 450-500hp). Cam specs are as follows

valve lift int - .534 exh - .553
lobe cntr int- 107 exh- 117
adv.dur. 286 int 296 exh
.050 dur 226-int 236-exh

also need carb suggestions or would my current Q-jets be enough?

Got some cams for sale or trade cheap if they will no longer fill the bill

Dave, you have to call Bob RMbuilder. He just knows how to make them run.

I second that, call BOB! I'm willing to bet you will just keep getting the same response from everyone else. If you need his number let me know!

good suggestion guys i hadnt thought of calling Madara. Yes i do need a contact number.

Bob Madara Marine Kinetics in N.Y. 585-654-8583

Great guy to deal with.

He did my cams in my new 502s this spring.

He will have you in some great cams with that exhaust and they will idle great also. Worth every penny.

Bob all the way. he set me up with all my internals!

My Build

462 CI
Dart 308's (box stock rect.)
Air Gap
Comp cam XM-270H
HP 500 carbs
Dyno'd with Imco wet manifolds

Here is the dyno sheet

How about converting to a hydraulic roller?

Kris Vogt

You will probably only be able to get 425-440hp with those cams and stock heads. Those cams are very close to stock 525SC/420 cam.
Some mild head work and roller cams should put you in the 475hp range, but it will cost you about another $1500 per engine.

I just did a Gen VI 454 last week 9.4-1 compression with stock 088 heads with a little port clean up, one of Bob's hydraulic rollers, some good vave springs and lifters, and a dual plane intake. It made just shy of 510hp and idles perfect, with good vacuum. A true budget build that rocks thanks to Bob's cam magic..