I was hoping to find something off the shelf. I spent a lot of time with Bob last month with a Gen V reverse rotation cam. Not really looking to go full custom. I would love to go roller but Mark IV kits are expensive. I will keep my eye open for one but I like having options. A future cam swap can happen later if I do not come across a roller by spring but what I really need to know is what you would run with a Flat Tappet and I guess a roller too. Just in case the parts god smiles on me.
Thanks for the help everyone.

If you already have the crane cam I would consider putting 1.8 rockers on the intakes and exhaust. You may have already considered this. This would perhaps help you achieve a little more until future roller cam. On 1.8's - exh. .576, int. .554. It would give you close to the 502/465hp cam without all the duration. Just a thought....

Now there's a thought. And should be a lot cheaper then buying 2 more cams (flat then roller).
So you think the 465 cam would work or just get me by? I really want to see a change this time even if I have to bite the bullet. After I found this motor in a corn field in PA I built it pretty much stock 330 mercruiser and it was OK but..... This past spring I did the square heads and speed pro .210 domed pistons and the cam, springs, lifters and pushrods mentioned before. I am sad to say it just didn't seem worth the time, money and work to change it all out.
Nothing like when I changed out the Thunderbolt ignition with a MSD type. 200rpm's @ WOT out of the box.
So if it is between me have big smile on my face or a ho hummm look I will buy the other cam even if it turns out to be temporary.

454 with 4.25 stroke crank is 482 cu. in., .030 over bore is 489 cu.in.

The 132561 is the cam mercury uses for the 420, as well as the 400-405-425-525SC.

The 134561 is bigger, he has the 132561.

Also you could buy the correct hydraulic flat tappet stick cheaper than a set of rocker arms.

I know what your going through and can probably only imagine what's going on in your hampster cage when it hits the pillow at night. LOL... Just know only you can decide what's best as far as how far you would like to take your project. It's easy for me and others to say what to do however ultimately it's your money but don't forget it's also the smile it brings to your face when it's all said and done. All good forged internals are important to help make your new engine last. A good balancing of your internals are equally important.

However at this point it sounds like what's the biggest bang for the buck. You did right by stroker crank in my mind and I'm pretty certain everyone elses. Like the old saying goes "no replacement for displacement" Your camshaft selection as well as heads will determine just how big that smile is on your face. If it were me in your shoes depending on how much money you have at this point to stick into it is go roller cam. You'll never regret it. Your exhaust is also very important however can always be changed out easily down the road provided the cam you choose know will not cause reversion. A good proven cam grind that has been around for years and is still used by several speed shops is the Crane 731 and 741 grind. Personally I would go with the 741. More Power Racing just north of GR, MI uses it for many applications from your cubic inch on up including blower engines. I can get you their ph number if you wish to talk to Dick Esch, the owner about it and it's ongoing proven results on the dyno. Just tell him John Read said to call. Their are still many of these cams around new and used. If you can find a good used set up with hyd. roller lifters go for it. Just do a search on it. With your cubic inch your on the edge as to stay with a dual plane or a single plane intake. A dart might help you a little on top end however you may sacrifice a little down low. I went with Dart intakes however was originally going to go with the air gaps. Twins tend to help one another out a bit so I went with Darts. Again your can always find these parts used as long as you look for ones in good shape. You'll see just as much gains in after market heads as you will with a good roller set up. Again you can always change these out down the road easily. Unfortunately your at this point whatever you do from here on out is what is going to really make the difference in my opinion. So in a nutshell I would go roller and stay on a search for a good used set of heads with the right cc chambers as well as exhaust. Probably sounds easier than done however this time of year people do a lot of upgrading so be sure and keep an eye out.

I started out last winter pulling out my 454's and planned to freshen them up a bit and put some thumper sticks in them and call it good. NOT... I ended up stroking the engines with all good forged internals. Then the cam I really wanted due to the power I wanted to make I ended up having to go larger intake runners. So then I purchased a couple of sets of Pro 1's 310 cc heads and Dart intakes. Then realized the Gils wouldn't make is much power as the CMI's would for my application so I ended up getting a couple of sets of those. Now after I have everything together I have decided to go with BG Mighty Demons because they make more power than the Holley 800's I had. The **** never stops. Next is my ignition. I have the stock TB system only because it ussually works flawlessly however I know I could gain a little from that as well. That will be next.

Just know what ever improvements you will make you will not regret. OK maybe you won't be able hit the bars as frequent or spend your money elsewhere as much but it will be all worth it. Sorry to ramble however I know how you feel. I am not an expert by any means and this is just my opinion. Everyone is entitled to what they feel would be the right thing to do and you can decide what is best from this point on. At the very least it is interesting to hear some opinions.

Good luck for now.
John

If you decide to go hyd. roller this cam would work great in your motor. Teague uses these in his smaller strokers. Some day I would like to up grade to this but right now my motor is running to good to convince me to spend the money and change anything.

http://www.jegs.com/i/Crane/270/1390...ductId=756865#

That's the same basic grind as the 168731 cam. I don't recall what block you have however if it's the Mark 1V then refer to the 139011 (above) or otherwise the 139021 would be the 168741 cam. Jegs has that also.

I always here people refere to these numbers, 731, 741. Who's numbers are these, Mercury?

They are Crane numbers although I'm not sure how they came abouit. They are a couple of good grinds though.. Been around for years. Custom grinds are always a good thing as they taylor your application however Crane did well with these. More Power Racing and another individual acutally came up with the 741 grind. It was year ago but still works well. Some of the Old timers had their **** together also. Both grinds work well with several applications. Cams have alsways intrigued me, I just wish I had some of the brains these guys do who come up with them.