Restoring Rusty

[rich weyand]

Originally Posted by Gregski

350HO Deluxe Engine (19210008) Specifications

Specifications Part Number 12487544


Set spark timing at 32º before top dead center (BTDC) at 4000 RPM with the vacuum advance line to the distributor disconnected and plugged. This setting will produce 32º of total advance at wide open throttle (WOT). The HEI vacuum advance canister should remain disconnected. This engine is designed to operate using only the internal centrifugal advance to achieve the correct timing curve.

<sarc>Wow. They've redesigned how gasoline burns! Impressive.</sarc>

Uh, no. Complete nonsense. Same thing on the instructions for the 350/290hp crate engine. BTDT, it's wrong. Higher vacuum ==> lower cylinder pressures ==> slower burn ==> earlier spark required for best performance and mileage.

Trust me, I've done a lot of research and experimentation on this, and I had a lot of access to people who know what they're talking about.

Read this for the real skinny on ignition timing.
http://67-72chevytrucks.com/vboard/s...d.php?t=689321