Hi, new here and in need of a camshaft for a 403 build that I'm assembling for my towing rig. Truck is pretty much a single purpose vehicle that I bought to tow an RV and also boat and race car.

I'm very open to buying from one of the site sponsors if a custom grind would be best. I've used Straub on several other builds, but he says he is about 4 weeks behind right now.

2001 chevy dually 4x4 , weight 6400#
4.10 gears
4l80e
Would like to retain stock intake, exhaust and convertor.
317 heads, mild hand pocket port
12 cc dish pistons with 9.95 compression
Nelson will do the tune

Tow the 7000# RV at 60 to 65 mph which is 2100/2200 rpm in OD.
Car trailer and boat tow speed can run up to 80 mph at up to 2600rpm

Thanks, Scott

 

Cam Motion has truck specific cams

 

We have quite a few truck specific cams as well! Pm me and we can get you fixed up!

 

Thanks for the replies.
I've been looking at the Vinci ultra torque
210/218 .551/.551 116
But the description is for a 5.3 / 6.0 so I wasn't sure if that would still be best suited for a 403.

Chris at Comp recommended their LSr 54-455-11 which is
216/233 .604 / .610. 112
The .600 plus lift and requiring dual springs concerns me that it may be hard on valve spring life.

 

I'd be a bit nervous with over .600 lift on a tow vehicle as well, I agree that seems like it would be tough on the springs

 

.600 plus lift does not require dual springs. There are several great choices for single springs that will handle that kind of lift.

Lift has little to do with how harsh the cam is on the springs. Ramp rates and lobe design are much more important. And with soft Cammotion lobes there will be no problem even with .600 lift.

Put it this way...a .560 lift cam on XER lobes is going to be significantly harsher on springs than a .600 lift cam with LXL or Cammotion lobes.

 

Agreed, I'm aware of single springs such as the pac and psi that would work. But comp specs their dual springs for that cam.
Also my understanding of the comp lsr lobe is that it is somewhat aggressive, which is what prompted my comment about spring life. And, that cam was designed more as a performance cam for 4.8/5.3 engines in trucks.

I was just saying that I don't feel it is the idea cam for my application. Although it is probably the best fit of the comp shelf grinds.

 

That's why you should be going with something like a Cammotion custom or truck grind with soft lobes for long spring life and reliability.

 

Why shy away from over .600 lift? The lobe itself just like redtan said is what makes the difference. In my experience you will nearly always see an increase esp on torque from more lift. If the stock head can flow more than .5xx then why waste its potential? There are many ways to skin a cat. But we have alot of experience with trucks as well and towing and hauling heavy loads. Not just selling parts and putting cams in a software program. A quality set of dual springs like the BTR or Lunati etc can keep you where you need to be on stability and longevity. Comp has so many lobes why limit yourself. Same with cammotion etc. If you want an idea, just pm me.