Setting timing?

[Charlie Darwin]

I have a 1984 GMC High Sierra with a 305. I was wondering if anyone on here knows what the timing should be set at, I have looked around and I keep getting different answers. I found one answer that said between 8 and 10 degrees btdc is good enough but then i found another answer that said 6 degrees btdc is where it should be. Does anyone here know for sure?

[donut]

If you want "official" timing, I'd have to look it up.
10-12 btdc will run better, of course your results may differ. (if it pings, back it off)
I haven't had any problems running 12 in my smallblocks.

If you really want to dive in, SBC Ignition Timing.

Welcome, I'll see if my Haynes manual has anything.

[INSIDIOUS '86]

My emmissions sticker on my truck says 4* initial.

That's good for emmissions but its still garbage
Start a 10* and then try 12 but ten should be fine. I don't go higher unless I fix the distributor to keep full advance under or at 40. Then I limit how much advance the vacuum gets.

All that won't do **** for a 305. I set mine at ten and put one med spring in the advance mechanism and that woke it up
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[donut]

Haynes manual lists 4 (fed) or 6 (Calif) btdc. Like INSIDIOUS '86 said, these were for emissions.

[motornut]

Originally Posted by Charlie Darwin

I have a 1984 GMC High Sierra with a 305. I was wondering if anyone on here knows what the timing should be set at, I have looked around and I keep getting different answers. I found one answer that said between 8 and 10 degrees btdc is good enough but then i found another answer that said 6 degrees btdc is where it should be. Does anyone here know for sure?

Hi welcome
my 79-2B-305 is about 10-12 advanced

[86c20]

the way i was always told and have done is start at 10 if you are at sea level and see what you get. if you are good keep turning it little by little till you get ping under wide open or kick back on the starter and then go back 3*. it will be less in the higher alt.

most of mine are at the 12-15* mark and run great with good response and milage too

[piecesparts]

Just keep in mind the more retarded the timing is set, the more heat is created in the engine. The information above with the timing at 4 degrees (federal) and 6 degrees (california) is what the manual says. I always ran my engine at 12 degrees and did not get detonation. I now have my timing set on my 383 stroker with an advance timing light and I set the timing at Total advance at around 35 degrees. I have had no issue with that setup. I live in Kansa and we are quite a ways above sea level. I agree, start at 10 degrees and play with it.

[superwade57]

I run 14 initial on all mine with great results. I've never dynoed them but have great results my total winds up being 34-35
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