Im considering 2 cams but open to suggestions.

Lunati bracket master 2
Or 270 magnum comp cam.

I have 400ci.
750cfm carb
Wieand intake
TMI pistons (9.5:1 i belive)
Ported stock heads with screw in roller rockers
Stock crank and rods
C6 auto.
Probably forgetting something because that list looks too short. My truck is 78 f250

I want this truck to be mostly a show/street truck. I love how the lunati cam sounds but it might be too big of a cam. My engine machinist (where i got heada and intake) recommended the 268 HE cam and i ASSUME that the heads had the 268 kit (springs and such) since they were remaned.. But didnt know about the other parts of the build.
Would those springs hold up to the addition lift of the lunati or would the 270 magnum be better?

I plan on switching to a manual and if needed id buy a trq convertor for the time being

 

I have the 268 Extreme Energy in a 408W with AFR 185 heads, 9.7ish compression, Weiand Stealth intake in a classic Bronco. Not a bad cam but even at the mild you do lose some off idle power. Not extremely aggressive sounding.

Any like cam (flat tappet, roller) from one company to another is not going to be significant difference from any other vendor. You can only make ramp profiles to a certain point. No manufacturer can defy physics that others can't meet.

Now here is what cam manufacturers can do. They can change center line and lobe separation angles. Each will make modifications to the torque curve. A lot of the aftermarket cams are ground with advance ground into the cam which helps lower RPM torque. A tighter lobe separation angle has also been proven to boost low end torque in carbureted engines. A tighter lobe separation angle will also make a smaller duration cam sound more aggressive as you are forcing more overlap between the valves and that is what gives high duration cams their aggressive sound. This will hurt your engine vaccuum as well if that is a concern. Look up lobe separation angle shootouts on the internet.

I have been thinking of swapping the cam out in my 408W because they screwed up and gave me a 302 vs 351 firing order. I was going to have the 268 Extreme Energy lobes ground on a 105 or 106 LSA vs the stock 110. This will boost torque across the entire RPM band and give me a more aggressive sound probably similar to the 274...which is a win win situation it most motor enthusiasts.

Gearing needs to be a serious consideration when picking a cam to. More duration cams need gearing changes to keep the RPMs of the engine up in its happy zone. I have 33s on my Bronco and 4:11s. The cam and tire size would not be as desirable with 3.50s.

 

So which cam would you pick? Or would you stick woth the 268? I want low end torque but the aggressive idle. I think the 268 seems a bit small for a cam and would like something a bit bigger

 

"Small" is a mans ego talking. Yes a small cam does not make big peak horsepower numbers, but it makes up for it in the lower RPMs with more torque and hence more horsepower in the lower RPMs which means a faster car at RPMs you are going to be seeing on the street. Horsepower is nothing more than torque multiplied by the RPM at which the torque is made, then divided by 5250. Big cams make better torque and higher RPMs and thus more PEAK horsepower. Peak horsepower means diddly squat for a street car as you aren't driving it around at 4-7k RPMs...and you don't have the engine components to support a big cam either.

I used to have a 100hp diesel Jetta that would blow the doors of the Honda Accord I have that claimed to have 140HP. The reason is that the Jetta had almost 100hp from 1800 RPM to 4500 RPM because of all the low end torque. The Accord was a dog until it got up to 4k RPM and got in its peak torque zone. Proof that peak horse power means absolutely nothing.

Even valve lift doesn't mean much. You can go from 1.6 to 1.7 rockers and get about 0.030 inch more lift on the XE 268. Many dyno test have been run that shows it is almost a moot point and some have shown to even lose power.

I would have them grind a custom cam with the lobes off the 268 Extreme Energy but on a 105 or 106 lobe separation angle. Or a similar spec cam from any manufacture.

It will probably sound similar to the next step up in cam the XE 274 if you want to see how that sounds on Youtube. Not sure if they have this cam for the 351M and 400M but they do have it in the Ford small block section and should be able to put it on a different engine family cam.

It is somewhat of a cake and eat it to story as far as sound but still low RPM power...but only a few bites...not the whole slice.

It is in the range where someone will be able to tell it is an aftermarket cam by the sound, and you still have a power band in a realistic RPM range that works with the rest of your engine components.

 

I'd say the 268 is a good choice and should still give you decent vacuum.

 

I will give my opinion on your next thread for the same topic.

 

Haha it's kinda like Groundhog Day.

 

This is so true. I still have a 06 TDI Jetta with the older 100hp PD motor. I love it and would swear it makes more than what they say but it's that torque....can't beat it.