76 F150 390 cid-timing

[pricej3]

I have a 76 f150 w/390. Just replaced the carb w/ holley 4160 and tuned up. Been sitting awhile. under medium-hard acceleration getting detonation/lifter knocking. Want to check timing but can't find any specs. With the light and vaccum advance plugged, 12 degrees, with vaccum plugged in 24 degrees all at idle approx700-850 rpm. Under hood stickers gone. Distributer has been modified I think, not points. Has a spoke assembly on the distributer shaft. Not to familiar with fords. Also, any good books or websites on tuning ford with a holley etc would be appreciated.

[unclebubbles]

The spoke thing you see in the dist, is the armature for the solid state ign system. Ford came out with solid state in 73 i believe, in 75 a few trucks still had points, and by 76 all had solid state i think. 12 degrees is a good starting point for the timing, but you can forget about the factory specs. The specs were written back when gasoline was real gas instead of the garbage we get today. The best thing to do is keep backing down the timing till you quit getting pre ignition. Alot of other things can contribute to pre ignition also. That engine probably has a good bit of carbon in the combustion chambers, and on the tops of the pistons and valves. Carbon deposits can get red hot and cause pre ignition. Also, the new carb may not be jetted quite rich enuff for the 390, a lean mixture will cause it. Check your spark plugs and see what they look like. Are they blisterey white? Are they brown, black....? Also, you can take the bowls off and see what size jets are in it, and pick up a few sets a few sizes bigger, theyre not that expensive, summit racing has jet kits for them or your local auto parts can probably get them for you. Heres a site that may have some info for you:
http://www.ford-trucks.com/forums/index.php

[pricej3]

Thanks, I'll probably de-carb this weekend, and back it down to 10 degress and check the plugs.