Pinging just off idle when taking off

I have just put together a 426 with an Eddie intake and 2 afb 600s. 284 484 cam, alum heads, and msd. Just now got it running and when I give it the smallest amount of gas it rattles like heck. If I work past it to get more carb involved it seems to do ok. Comp is a guess but i would think 10 or 11 - 1. Do I need to try 100 oct from the airport, I have played with the timing and it still rattles just off idle. Any ideas would be appreciated. Thanks.