my 440 is having some spark knock after warming up and during acceleration. I had put regular gas in it before but now use premium and have autolite plugs. Is there a good way to fix this?

Back the timing off until it quits pinging.

Timing won't always resolve it, depending on your CR. And if timing doesn't take care of it, you might do well to try mixing in a little race gas. That's what I have to do because I run full advance (36º total) all the time.

Dale

I've been messing with the timing already and that hasn't helped. How much race fuel would I have to add in and I don't even know where to get any

Where you at in Michigan? There are some stations here local to me that sell it. I have also heard some Speedway stations have it.

Before jumping into the "race gas" bucket, what compression ratio are you running. What are your cam specs? How much total timing? When did this start pinging, or has it always pinged? Need some info to help you.

The engine is mostly stock except it has a bigger cam but not sure of the exact specs I'd probably say 10:1 ratio.Its always had the ping. My total time is about 38* and also I'm from Frankenmuth, MI

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The engine is mostly stock except it has a bigger cam but not sure of the exact specs I'd probably say 10:1 ratio.Its always had the ping. My total time is about 38* and also I'm from Frankenmuth, MI

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Thanks.
With 10:1 and iron heads, you'll need at least 93 octane. My experience, total timing, including vacuum advance, should not be more than 35* to 36*. I would actually disconnect the vacuum advance and "recurve" the distributor. Try putting 26* of mechanical advance in it and have it all out by 2000 rpm. This should give you 10* of initial. My Good luck.