[zrayr]

Stock 289 Hi-Po engines with a stock Ford dual point distributor (no vacuum advance) have 40 degrees BTDC timing at full advance w/ 12 degrees BTDC at idle.

That said, gasoline was formulated different back then. But I can still use those specs when running my Hi-Po 289 (stock 10:1 compression ) without the Vintage Paxton installed.

With the Paxton however I either have to dial back the full advance setting to 32 degrees, OR use a octane booster. Either method eliminates detonation (pinging).

Z. Ray