Working with a 1970 455. The engine has been gone through and looks and sounds like it was professionally done. The owner says it has a stage 1 clone camshaft. Seems reasonable it dose make nice low end power. Question is what do most prefer for total mechanical timing on a street performance car with stock converter and 3:42 gear?Thanks
Depends on several things, the altitude, vehicle weight, what distributor is in it etc, start at 30° and see what it likes 30° to 36° is the general window
X2, you have to determine what YOUR combination likes. There are no short cuts, you have to experiment. Best place is at the track. If the engine wants more timing, it will produce an increase in trap speed when you give it more timing. Buick distributors topped out at 30-34*, so I would start at 32*. Disconnect the vacuum advance, and make some WOT runs from various speeds. If it pings, retard the timing.