pdq67 said:400 piston info, only for reference!
I finally figured out I have L2410F's in my 406 b/c of my double-hump heads.
They are the full bowl, four notch TRW's that have the 3/16" to 1/4" chamfer around the outer edge that is "supposed" to help blow the new gases out of the open area behind the quench ring area. They do have about a 3/16" quench ring around them.
NOT the best in the world, imho, but I got them before I knew anything about this stuff way back there due to my -461 double-hump heads.
Forged stock type TRW 400 pistons with four valve notches are as follows:
1970 = L2352F, .088" deep full dish, very slight chamfer;
1971 to 1973 = L2376F, .160" deep dish, slight chamfer; and
1974 and new = L2410F, .185" deep dish, big chamfer.
If I had it to do over again, I would run "D" shape dishes like is being discussed here.
Hope this is of interest to somebody..