With that thumper cam, it needs at least 20 degrees initial timing and probably 34 total mechanical advance all in at 3,000. Also, what spark plugs are you running?
First order of business is bumping the timing up. 227at.050 and a 107lsa needs way more then 10 degrees. Once you get the initial to a reasonable spot without pinging with the fuel you use you'll have to go in the dizzy and adjust the total at 3k ish rpm's to get that in the 36 degree range. Once that's takin care of you can mess with the carb if need be.
The two answers above are what I would have said. I was just running the big 227 thumper in a 10.5-1 - 360 w/Edelbrock heads and the chink AG knockoff intake with a 600 AFB & headers.
Back that initial up to 20*’s and limit the total mechanical advance to the as stated 36*’s which is about that sweet spot of the stock iron heads. Use the black bushing. That’ll get’er done fur ya!
