after a terrible day with the chevelle yesterday worked on it today

[SS Shaun]

so after a really bad day with the chevelle yesterday i got back in the garage and starting trying to tune it some more. I was told i had a miss fire and my rockers needed to be adjusted. So i thought i did it right and it was an epic fail. I got massive back fires when stepped on the gas and it was all over the place. I took my time following the distributor position 1 and 6 method. Made them all loose as can be and then adjusted from there. Started the car and i plugged in my timing light. Timing at idle was very high so i knocked it down in steps. Got it down to 18 degree at 900 rpms and max timing at 3100 rpms was 33 degrees. no more back fire no more miss from what i can tell. so my question to all of you is this. Is timing at 18 degrees idle and 34 degrees at 3100 rpms good for a 454? temps stayed right at 190 degrees the whold 45 mins the car was on. took it around the block and got on it pretty good and no more back fire. Suggestions?