Gears and a locker are on the short list. I’ve been fighting this truck for a year and had issues with the 350/350 in it, ended up with maybe 4 miles on it? So I decided to give an LS swap a go. Thanks for the input

 

Yeah the Speed Engineering header are the "go to" most members here use. Great quality and fit plus they are well priced. On the mounts a lot of LS swappers use the Dirty Dingo Motorsports "slider" mounts.

 

So after researching and debating it I’m sold on the TSP stage 4, but im not convinced on the high lift. What kind of real world gains would I see vs. the low lift? And is it that much harder on valve train? Am I going to wear stuff out? Or is .600 still pretty mild in the LS world? Also what dual springs are most people running? I’ve found about a billion options.

 

Yes higher lift is likly to make more power especially with a good head, but even so with a factory head.

Yes more lift will cause for stress on valvetrain.

Yes I reccommend dual springs because even if the springs are well within spec to the cam they can fail and that costs a lot more than dual springs do up front.

Best option probably whatever is on sale.

 

It will cause more stress, but that lift for that duration is not super aggressive compare to others. Note, they also have the same lift for their Stage 2 version which has far less duration.

 

Low lift versus high lift

 

Im not sure how far to take this thought but... I had someone explain to me once that high lift is softer on the valve springs because the arc of the lobe is actually a smoother arc with higher lift. When you get into decent duration and low lift and with lobes designed to get the valve up off the seat.. you end up getting more of a squared off arc than a smooth arc. You'll have to picture the cam lobe profile with a ramp to get the valve up then kinda maintain that lift then drop off. Where the higher lift gets it up off continues raising then starts to arc back down.

 

Not sure I follow. Are you saying the longer duration would have more stress?

The shorter duration with same lift will (in general) have faster ramp rates. The force acting on the camshaft, lifters, and springs are based on the mass of the system and it's instantaneous acceleration. That acceleration is increasing with the faster ramp rates, therefore the force is going up. Plus the valves closing faster are putting additional stress on the valves and seats.

 

I was getting at lift

Lets say you have a long duration cam with really low lift, and a lobe designed to get the valve up off the seat quickly, the arc will need to flatten out then drop off again, resulting in more of a squared off shape. That would be less pronounced with higher lift, being easier on the valve train.

And just like you said the lower lift is likely to have a faster ramp rate, faster ramp rates can also be harsher on the springs.

 

Ok, I think what you're referring to is not a typical cam design, but a special case where someone is trying to work around a spec limit to fit within a particular race class either circle track or drag. In that case, they accelerate the lift really quick and then have a rapid transition to keep a long dwell at the nose to make up for the lack of lift. In that case, yes.

However without this restriction, they don't design with a such a rapid change, so low lift doesn't automatically translate to faster initial ramp rates.

I was saying the shorter duration for same equivalent lift has the faster ramp rate. See the illustration in my post. They have the same total lift, but the dotted line on the exhaust side for example, has a faster ramp rate. And that rapid transition of the nose, will further stress the valvetrain.