Are there any modern off the shelf options?
I got a deal on a lightly used blueprint engines 408LA stroker that has a magnum head conversion. Current cam is the old style .238@.050 .474 purple shaft. All I am finding is dual pattern cams which I don't need with magnum heads and headers.

You may not need it, but dual pattern cams can have a serious power advantage, and from what little I know, are very effective. I put together a 408 with Magnum EQ heads, dual plane intake, 10/1 compression. Cam is a Comp Muthr Thumpr with 235/249/ 107 LSA duration. It made 500 hp from 5200 to 6100 rpm,519 TQ at 4100. You can and probably should have a custom grind made just for you.

Educate me. I thought the only purpose for a dual pattern was to help out the exhaust side when needed. Magnum style heads did not need the help I have read. Is there more to it than that? Thanks.

Call Jim at Racer Brown and have him grind you something.

The dual pattern cam is highly overrated.

As a second thought...the intake port is so small and weak for most engines you should be running a dual pattern cam.

It should have 10 MORE degrees on the intake. Not more on the exhaust.

Also, is a dual pattern cam less intake duration or more exhaust duration?

Howards cams has a number of single pattern cams and I think the lunati street master line is all single pattern. Don't just look in the summit catalog. On thier website I think single versus dual pattern is something you can filter in a search.

Also go to the sites for lunati, comp, etc.. and download their catalogs to look.

FWIW I don't recall magnum heads prefering single pattern, I thought the 308 LA head was the only one that ran better with single pattern.

and if you are looking for off the shelf, Hughes Engines has a wide variety to choose from. They are the small block Chrysler guru's IMO.

Bought numerous things from Hughes, but looked at their website and it was all dual pattern. Maybe I will give them a call and ask why? Thanks for your help sir.

I should have said magnum style head conversion. It will actually have a set of the Indy RHS heads that have been prepped. Dual pattern can be either way, but the off the shelf stuff I have seen has increased duration/lift on the exhaust lobe for the small block.
Thank for you help.

Take a look at the lobes at Comp Cams, especially the XL-HL series

Fun part of all this is
You can take 15 cams that are in same family size wise from every maker--dyno back to back and you will be surprised how little diff there is--YES one will make 20 more HP on a 500 HP build but almost every 408 back yard built by anybody with any hyd cam --guys doing one engine not engine pros--will be between 475 and 500 HP so ....it is not a life and death deal--you select a cam that is not too big to live with and drive the way you intend to drive and go with it simple as that--who cares and who will know that it is 475 or 495--big deal
Single pattern cams work Great --dual patterns are way over rated

Am probably looking for a cam for my new 418, and Dwayne liked a single pattern for it over a dual pattern i was considering.
Should have said its a solid flat tappet

I have found that the 238 ish range in a 408 makes a great street car and driver at 475 Hp range( with zero effort-no porting etc) and to make 500 plus they seem to like a lot bigger cam that is not as good on the street / vacuum etc
Love that idea of a solid!! They make some steam and are so much cheaper than a roller

Nothing is a for-sure thing with cam design, and it's always a case of "it depends." The only sure thing is the answer doesn't come from a catalog or a web site.

I'm still amused by a magazine article from years ago that was supposed to show the merits of a well-known cam company's new series of dual-pattern grinds. The test compared it to one of their older single-pattern designs. The old cam, IIRC, made more torque, made almost as much HP, and was more stable at higher RPM. I don't recall how the article tried to spin the results, but it didn't do that new cam series any favors IMO.

I still use a lot of single pattern cams....... And some of the builds I've been happiest with had one in it.

the only purpose for a dual pattern was to help out whichever side needs it.

and one side or the other almost always needs it.

In my low comp 440 I ran an Isky mega cam 292, which is 244 @ .050 and 108 lsa, .505 lift. It sounded good and ran/pulled great.

Sometimes the bias can be tweaked toward the intake side with higher ratio rockers (but this generally doesn't work on the exhaust side, which is more heavily dependent on the XO opening point than lift).

As I have posted before, the only reason why manufacturers use the same lobe and rocker on both valves is: it's the cheapest way. They try to get the ports to work that way even if it's not particularly efficient.
The function of the two ports (gas speed, temperature, pressure) is as different as chalk and cheese, and their needs for an event are very different.

The say on whether dual pattern will help should be your porter as the final analyst of the relative port capacities.

Make sure the cam you choose is a Mopar cam designed to us a .904 lifter... most of those shelf cams are Chevy grinds.

www.jonescams.com .Mike Jones
www.camcraftcams.com ... Charles

Sometimes, a little extra exhaust can help cylinder fill. But this and many other factors of cylinder filling and optimum efficiency in a given parameter (engine/cam rpm range) can be a huge trial and error experimentation. There are so many things to look at and consider when that cam starts turning.

On single pattern vs. the use of a split duration cam, I have found best results with a split pattern and stock heads. Why? Because the exhaust could use that help? I think so. On ported heads, I haven’t seen any real advantage with a split pattern and the single pattern ran quite nice.
No 1/4 slips. Just basic street builds.
Still playing around with cams in the various engines.

While this thought/idea may not play out accurate, perhaps a computer sym like Desk Top Dyno could be helpful in at least show what could happen with a different cam. If anything, it could be a helpful tool in showing what is possible/probable.

Have there not been published reports on flow balances between the ports and suggested cam specs for such balance

Depending upon what the end user's goals are, that's not necessarily a "must have", IMO.

Even some of those that have been advertised as designed for a .904 lifter are lobes that could probably work OK w/ an .875 "Ford" lifter, since the cam designer(s) didn't set them "on kill" as far as using the full lifter foot diameter.

Also, "Faster" isn't always "Better" when it comes to cams, but it seems to me that most people don't want to believe it. If you want to turn some RPM with a hydraulic cam, the fast rate-of-lift lobes are also more likely to experience valve train "crash" at a lower RPM than a less aggressive lobe.

They may help to show trends, but the more I used even a fairly high-end simulation program, the less I came to expect results that reflected the real world (at least compared to my experiences).


Well... there have been lots of magazine articles that attempt to simplify things to that level, but the reality is it's not that cut-n-dry. There are too many other variables that influence things (e.g. CR, RPM range), which is why IMO it's better to work with someone who is familiar with the type of engine & combination you have.

I have never owned a dual pattern cam. I have been 9.60s 1/4 mile with a junkyard headed Stroker SB, LA 587 smog castings, in 3000+ car with 727/Dana 60. Racer Brown STX-22 SFT Cam was actually made in 1971. In another tank car, 4200# 79 Chrysler "300", with another stroker SB with same junkyard 587 heads and a Racer Brown STX-21 SFT cam, has been 11.20s at 118 mph. In another car with a Indy SR headed 512 c.i. BB with another RB STX-22 SFT cam, have been 8.50s at 157mph. Car is a 89 Chrysler LeBaron and weighs just under 2600#. Have never lost a lobe on any engine in any of my cars, except one that was a used cam, someone gave me, with new lifters.

As someone in earlier post said already, Call Jim at Racer Brown. He will set you up with a perfect camshaft.