read thru these threads above carefully and take the time to use the calculator links with YOUR engines specs
almost every choice made will be a compromise in some area, a wider lsa tends to broaden the torque curve, a lighter weight car with transmission gears /gearing that spreads the shift points out with rear gearing like lets say a 3.54:1 ratio, and a th400 and a nearly stock stall converter speed will do far better with a wide 112 lsa with a cam of similar duration compared to a manual trans car with a 4.56:1 rear gearing,that can more nearly control its shift points exactly to the power curve, where a 106-108 lca may produce a bit more peak hp but sacrifice a few hundred rpms on each end of the power band .
a larger bore to stroke ratio tends to slightly favor a wider LSA, so lets say if you compared a 509 BBC with its 4.5" bore and 4.00" stroke would tend to work a bit better with a 110 lsa than a similar 496 BBC with its 4.31" bore and 4.25" stroke, where a 108 might work better, but head flow, compression and your header design also effect the results, most guys just play (FOLLOW THE LEADER) in that if their buddy's car runs fairly consistently with a similar combo to their car they look at his results and order a similar cam, while that tends to produce a similar result its not calculated to produce the maximum power, or ideal results, that correctly matched components would produce, being consistent is great but that's not necessarily the same as having the most effective combo possible, for a given bore/stroke/compression ratio,rear gear/etc.
if you take the time to use the calculators you can match several factors, and produce a bit more efficient flow thru the cylinders and a bit more effective use of the cylinder pressure curve
I'm sure you've seen guys that build engines that were designed to spin 7000rpm plus who eventually find that they get their best results if they shift at 6400rpm, that's usually because the cam may be designed to spin 7000rpm plus but several other components are not designed to produce the max power in the upper rpm range or the gearing doesn,t match the power curve.
in case you don,t understand the chart, you take the engine displacement PER CYLINDER divided by the valve diam. then you use that on the chart to locate the lsa
lets assume youve got a 383sbc, 383/8=47.88
divide that by intake diam., lets say 2.02 and you get 23.7
youll see the ideal is near 105 lsa, but then you ask,WHY are most cams ground with a 110-112 LSA
its because that tight lsa may maximize the peak volumetric efficiency,and peak hp/torque, it will also be far from ideal at low speed, with a lopey idle, or for emission testing or for ease of low and mid rpm ease of tuning or for sensors to read because of low rpm reversion in the intake runners.so a compromise with a wider LSA is used, sacrificing a bit of peak hp for better average drive ability and lower emissions and better mileage
look at the chart,
its not comp cams products that are usually a problem, they tend to be similar in quality to several other manufacturers, its just the fact that I, and several other people have consistently gotten lets say LESS than the BEST ADVISE, and inconsistent advice from their tech guys , you can have 5 guys call 5 times with the identical info and get 5 totally different suggested combos or cam specs,they remind me of those tech help computer guys that are in India & Pakistan, etc that read of a flow chart,and if your combo doesn,t exactly fit their flow chart your screwed, so I personally tend to avoid them