Some cars came with more of a performance curve. Actually, any older 2bbl car will benefit when somebody curves the distributor, and pulls more initial timing. For instance, a stock 318 2bbl in the early 70's may call for TDC or 2* BTDC. I usually end up running them around 10-14* BTDC, and if need be I pull some timing out of total advancement. A lot of times going with weaker springs for the mechanical weights is a benefit as well.