I have a 38 fountain with 420's in it now with victor jr intakes,h20 bypass and gill exhaust. I am wanting to go faster and I was wanting some input on my cams vs. hydrolic rollers and cyclinder heads.I am also looking at the edlbrock rpm performer rectangles or the merlin/darts. Any help I would appreciate

You have some of the good hp producing parts already. Going up from here gets expencive real fast. Roller cams and lifter sets are 900.00 per engine. Cylinder heads are 2000.00 or more per engine. Small stuff like gaskets add to that. You will also have to up your redline to 5600rpms to take advantage of the new breathing or you won't really make any more hp. If you do that 550hp is possible. Or you can supercharge and make the same or more. Your engine is a good base for supercharging with it's strong internals and 8.8 to 1 comp. ratio. Actually, your engine is the base for the Merc. 525.

I REALIZED LAST YEAR FAST, WHEN I PUT NEW GUAGES AND OTHER BOLT ONS ON HOW EXPENCIVE IT CAN GET.I KNOW I WILL NEVER BE THE FASTEST ON THE LAKE OR EVEN CLOSE,BUT I WOULD LIKE TO GO 70-72MPH IN FLAT WATER AND 75-76 IN 3-4 FOOTERS.THE REASON I DIDN'T REALLY WANT TO GO TO BLOWERS IS THE SEARCH FOR GAS AND DEPENABILITY (OF THE BLOWERS AND MY TRS DRIVES). 90% OF THE TIME I CRUSE 35-40MPH WITH MY FAMILY BUT I LIKE THE SOUND OF A GOOD HEALTHY CAM AND THE ABILITY TO USE IT ONCE IN A WHILE. I DIDN'T MEAN IN ANY WAY TO DISRESPECT TEAGUE MARINE ,BUT I'VE READ ALOT OF SPECS ON MOTORS THAT HAVE THERE CAM. I SHOULD HAVE POSTED HYDROLIC ROLLER PEROID.

If you want to make the most of a n/a 454, you should use HP500EFI cam. Pt.# 169621 from Crane. .598/610 lift, 230/236 duration @ .050. Use Afr 305 or Canfield 310 rect. port heads. If you want the best, order them cnc ported. You can also have them milled for .5 more compression. Aluminum dissapates heat better. Isky makes a roller lifter that can live with higher spring pressure. You'll need that to be able to run higher rpm's without valve float. I'm assuming you already have a Holley 800 or 850. Prop your boat to turn 5600.

PatriYacht - Isn't 5600 a bit high? I have those 420 motors, and actually I can spin 5600 rpm, but I was under the impression that I need more prop and should be around 5000-5200. Thoughts here?

I thought the hp500 cam was smaller than that or is it just the carb version? Will I have a piston clearance problem or check to be safe?I would love the buy best in cyclinder heads but money is somewhat an issue.I was looking in the 15-$1800 price range or would porting my 990 castings give me a noticable improvement.I haven't seen anyone really doing that or any flow #'s on them.Because the merlin irons are better out of the box than a ported factory 990 rectangle port. excuse the stupid questions but I've been spending stupid money on mustangs for a while and out of the bbc relm for a while. I would call a performance shop first, but I don't want to get a sales pitch on what they get the best deals on nor wast there time afterall they are in it to make money.Thanks for the help so far.

Your engine is already tuned for peak power around 5000 rpm. Going to a larger cam moves the power peak up. Not sure about the pistons. Have to check with manufacturer. Porting iron castings is expencive in itself and they would need a lot of porting. What I suggested will get you 100hp ea. and 5-7 mph.

J Winkleman.. if you are using Crane hydraulic roller lifters... part number 13532-16,, or part number 039901... be aware that those lifters were designed to run in automobile engines and not marine engines.. they work fine in a marine environment... BUT THEY WERE DESIGNED TO RUN IN NO THICKER THAN 10-40 OIL AT 200 DEGREES TEMP. Any thicker oil and the top end of your engine will be starved for oil... you will see rocker arm failure and spring failure if you run any thicker oil than that... I got this information from Crane Technologies.... Crane's tech department was very helpful in sorting out my problems with engine wear. Don't let some jackass tell you that you have to run Straight 50 weight oil because it is a boat engine. The lifters are very good and once I was running the correct oil I never had any more problems.. Good luck.

Thanks for that info Reed. Stock 420's are hydraulic flat tappets but I have Crane hyd. rollers in my engines. My next set will be Isky.

why are you switching lifter brands and how does the 500efi cams you suggested lope or sound campared to the 420's they look to have less duration and isn't the duration where the lope comes from.I'd like it to sound like my mustang but thats not possible and still drive it(690 699,278 285 @.05)at least under 5000rpm anyway