Surprised by the 114 in @107. Why such a wide lsa, are you trying to keep the vacuum in powerbrake territory?
It's to control overlap.
When you have too much valve overlap, you can basically pull the intake charge in and it doesn't get translated into power, it just goes right out the exhaust.
There are as many flavors of hydraulic roller lobes as anything else. Aggressive lobes can make more power if everything else is correct, but it gets tougher to control the valves/lifters at higher rpms, and in a street car, they can be noisy. Lazy lobes are nice and quiet and easy on parts, but generally speaking, they have a lot of overlap and it gets tougher to make good vacuum.
Just like everything else, you have to balance it and find that point of moderation that works for what you're doing.
The camshaft lobes that I'm using are Comp's HLO lobes, which are a good balance between aggressiveness to make power and laziness to make sure that I don't lose the lifters at higher rpm.
With a camshaft this large (259/267 @ .050" is a *very* large hydraulic roller, especially for a 390), the advertised duration is going to be high anyway. Even if you had an aggressive lobe, advertised durations would be over 300°. When I started looking at overlap, I had a ton. To decrease overlap, you either tighten the intake/exhaust duration spread, or you widen the LSA. I widened the LSA. I still have a lot, but in my mind, it's keeping that balance.
I had a member of my 351C forum contact me and asked for help back in the spring. He has a '69 Mustang, running 6.30's and he said that no matter what he tried, he felt like he had hit a wall with getting any more horsepower out of his combination. He sent me all his specs, along with a cam card from Crower, where they had ground him a solid roller. It had a tremendous amount of overlap for his displacement, lots of duration, with a 106 or 107 LSA from what I remember. I basically had a camshaft ground for him, with the same .050" durations, same lift, and decreased the amount of overlap by widening the LSA. It picked up a full mph in the 1/8th mile.
So long story longer, overlap can make or break a camshaft, and I felt I needed to tighten this one up a bit. I would have went wider, but on a typical FE billet core, you can only go so far.