[b-man]

A friend of mine built a 421 for me, a talented amateur builder who’s built dozens of engines for his friends and fellow club members.

He broke in the cam on his run stand and ran it for about an hour total.

I installed it in my car, never touching the distributor. After several hundred miles I put a timing light on it even though it was running strong and drove great. The initial timing was 5 degrees which was likely the stock setting. I’m sure my friend was being cautious and didn’t try to maximize the timing during the crucial initial break in.

I bumped the timing to 12 initial, added to the 23 degrees of mechanical advance built into the distributor I have 35 degrees total now.

So I’m sure the shop set your timing well enough to drive and enjoy your car just like my friend did for me, but when circumstances are optimal check and adjust as needed.