I suspect the 020 means twenty thou oversize.
So possibly been bored and reconditioned/rebuilt at some stage.
Measure the bore diameter if you have a set of vernier calipers, or better still, a micrometer and telescopic gauges.
Standard is 90.47 mm or 3.562" and twenty thou over should take it to approx 91mm or 3.582"
A good quality steel ruler across the top of the cylinder would be good enough to reveal if it's been bored out.
Cheers, Mick.
1974 S3 88 Holden 186.
1971 S2A 88
1971 S2A 109 6 cyl. tray back.
1964 S2A 88 "Starfire Four" engine!
1972 S3 88 x 2
1959 S2 88 ARN 111-014
1959 S2 88 ARN 111-556
1988 Perentie 110 FFR ARN 48-728 steering now KLR PAS!
REMLR 88
1969 BSA Bantam B175
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