here is the info on the cam i will be pulling from my motor
guy i got it from was also building a motor to run twins Reed hyd roller 232/232, .560/.560, 110 l/c, 270 adv
Less exhaust dilution with high exhaust back pressure to intake boost pressure ratios. A little more vacuum at idle. A little less chance of plug fouling. Cuts down on the overlap number.
The larger spread number makes a large duration cam more streetable. More low, midrange torque. Better spooling.
I have to add that I've heard that the Buick V6 is a pretty unique animal, and that it doesn't react well to too much spread, in a racing situation, anyway. Maybe the spread is more preferred for street manners, mainly.
