2020 small block race?

Ok starting with the same TDC car as the penalty box do these seem like realistic e.t.'s?
383 15.2
400 14.4
440 13.86
My problem is that the # for the increase in cid decreases with each jump of say 20 cid.
318 .05
340 .045
360 .0425
383 .0396
400 .0360
440 .0315
Just math and not sure where to take my baseline e.t. sources from to give a good run as 1/4 mile data is inconsistant.