02-05-2020, 11:40 PM
Re cyl heads, from contemp road tests, Forum members observations of stock RN vs RP performance etc I often wonder if the bhp output at rpm of the restricted 5.2 head is actually less than the 4.9, although it better at lower rpm. Heads all seem to be nominally 1.5 thick, a quick check for resurfacing. Squish speeds up the burning, renders engines harsh, so as pinging is not a problem no great advantage except that it fills up space and leaves room for reasonable gas passge.