What to set my timing at?

[chad1984chev]

Here is the deal.  I have a 1984 GMC truck with a 454 in it.  The 454 is out of a 78 Chevy truck.  I am trying to adjust my timing, but am not sure what degrees BTDC to set it at.  The engine is mostly stock.  It has headers, dual exhaust, Weiand Stealth intake manifold, and a Holley carb.  I hope this is enough information.  I have read all different degrees from 4 to 15 degress, so I dont know what to set it at.

[VileZambonie]

Initial timing really just effects idle quality and emissions. If you're running a GM HEI Hook the vacuum advance up to manifold vacuum and advance it til it pings when you romp on it and then retard it until the pinging goes away. Make sure it starts easy. If not retard it a little more. Once you have it set there you can check it and record your readings as your "good" numbers

[micahadams]

I have the same truck as you and in 84 they call for 4BTDC initial but my truck runs sligish with that little timing. I think I have mine near 13 initial

[mountaindrew]

I have an all stock 1986 454.  Factory setting was 4*, but 11* works good for me with no pings.  I run 87 octane and have stock HEI dizzy and vacuum advance hooked to full manifold vacuum.  BIG difference in performance and gas mileage from 4* to 11* too.

[bobcooter]

Initial timing really just effects idle quality and emissions. If you're running a GM HEI Hook the vacuum advance up to manifold vacuum and advance it til it pings when you romp on it and then retard it until the pinging goes away. Make sure it starts easy. If not retard it a little more. Once you have it set there you can check it and record your readings as your "good" numbers

Do you mean romp on it with it in park or running down the road? I'm guessing running down the road?

[VileZambonie]

Loaded going down the road at operating temp.