If you don't want flat tappet lifter failure, find some NOS lifters that are 25+ yrs old...or have a set of factory lifters re-faced.
Also, overlap is what gives you the throaty exh note, not LSA. All these 'trick cams' with the fancy names such Crumper, Whiptrash, Bootcrapper have 10-15* more exh duration to increase overlap. If the exh duration was reduced to be the same as the int & the same LSA used, the exh note/sound would be much more subdued.
