As far as low compression early IVC verse high compression late IVC goes with similar calculated DCR ratios, The first one is going to get better mileage and have less reversion at idle due to the geometry of things The later intake closing point will cause more intake reversion despite the increased compression helping it along. Past idle and very low RPM The rest of the valve events besides the later IVC remaining the same The higher compression combo should surpass the lower compression combo much earlier in the power band then you would expect.

The advance is just there to compensate for the wide range of applications said shelf cam will find itself in that it was not intended for.

 

The two single events that will most influence powerband are IVC and EVO. Early intake closing combined with a late exhaust opening makes torque at lower rpm by trapping more of the air/fuel charge on the compression stroke and using more of the cylinder pressure for work by trapping it longer. For higher rpm operation, need a later IVC and earlier EVO for increased breathing. Duration and Centerlines alter both.

 

High DCR improves throttle response and power before the engine would be capable of using that ram effect where a later IVC becomes effective. Symptoms of too much for a street engine would include difficulty loading the engine at the lowest RPM you would want to load it at. For me that RPM is 1100.

The only reason I have an aftermarket converter in my setup is because I broke the clutch in the stock torque converter playing with it between 1500 and 2K locked up in fourth gear on the highway. 60 to 80 mph at that RPM with a 49° IVC @ 0.050, The throttle response and torque is strong enough with my setup to ruin the stock converter clutch after a few short highway trips goofing around and blipping the throttle around that RPM.

My stock 4L60E survived without a scratch, she's still rocking completely original 20-year-old internals burning rubber through second gear . She got a fitzall TCC valve to kill the PWM and a Sonnax longer servo pin ground down enough to get rid of all that band slack from over 226,000 mi of sympathetic abuse.

Lots of factory cam timing has a bigger IVC number than EVO number, LS3 cam for example. 204/211 117-3

​​​​​​Most are afraid just afraid to give the intake what they give the exhaust. My cam has a 224° exhaust lobe on a 111° center line, Just like a single pattern 224 on a 110 LSA would. That would be a pretty awesome grind for a stock compression 5.7L wouldn't it? Well that's plenty enough exhaust duration for me and What I'm doing so I took that 111° exhaust center line for that very reason, however I've got even more displacement underneath it to cram through it so it's going to make a shitload of torque which is what I want.

Moving over to the intake side I've got the same displacement as an LS3 hell I have an iron LS3 short block. But I'm a boner and I put a 706 head on top of it so what do I do. I've got well more than 11 and a half to one compression probably 11.8 even more with all the carbon buildup and s***. Well the LS3 has a 2.165" intake valve and a 90 mm intake, I only have a 1.89" and a 78 mm intake, so mine needs a lot more "time" to fill the cylinder to even try to keep up with an engine of the same displacement with rectangular port heads. LS3 cam closes the intake valve at 42° mine at 49 with a much more restricted intake, think about it It's not a big deal at all, I stopped the intake duration at 220°, because I didn't want more than a -9° intake opening with my 1° exhaust closing to keep the low RPM characteristics in check.

If I was trying to make a really big power number with this engine I wouldn't hesitate to put a massive single pattern in it. Technically speaking with those heads on it it's just a 5.3L bored 0.285" over and those came factory with the single pattern camshaft.