2F Motors: Early to Late. Which is Best?

We did some digging for info on the 2F motor to try to put together a little bit on the various upgrades/changes over the years that were made. How does your year 2F stack up? 4.2L 4230cc 135hp @3600 RPM Torque 210 FT/lbs @1800 RPM 2F Block Castings 61011 - 75/76 61014 -Late FJ60’s Head Castings Open Chamber 61030 & 61031 Closed Chamber 61040 & 61070 . . . #LandCruiser #toyotalandcruiser #landcruiserlifestyle #cruisercult #thecruisercult #toyota #FJ40 #FJ55 #60Series #FJ60 #wa60n #2F #FJ80 #FZJ80 #UZJ100 #toyotausa #toyota #wagonlife #89nolder #landcruiserchonicles #ih8mud #tlca