Yesterday Ron Lockwood and I eventually had good luck birding Gate 8 area midday (returning from Skinner Mountain), though neither of us were familiar with the right spots to look/listen, particularly for ACFL. Below is some guidance to help others save time getting to target birds.
Gate 8 is at Packardville Road, turning east off Route 202 on the west side of Quabbin. You will see a sign for the bait shop. The area we had these birds was about a half back from the end of the road at Fishing Area 1, about two miles total from Route 202, where there is parking for $6. As you approach the end over the last mile or so, you should notice that you are paralleling a stream on your right. Listen for birds of interest along that stream. It seems okay to stop and listen from your car, but parking and leaving your car might risk ticket or towing per signs we read.
Also notice two speed limit signs (on left of road, facing AWAY from you), first one dark green and then one white, along the last half mile of road. We could hear both LOWA and ACFL from the road roughly between these two signs.
After legally parking, walk back up the road to a spot roughly halfway between the two signs, looking for a spot of easy entry into the woods to get to the stream, now on your left. You'll have to go up and down a moderately high embankment. Our entry spot offered easy walk to stream with little impeding understory vegetation.
At the stream we got great looks at the singing ACFL but the LOWA had gone quiet when we began looking for it, about 2 PM (ACFL then quiet, too). Even after that we also heard a grouse drumming twice on the other side of the road.