I had overhauled a 2.0L IOE engine from a 1956 86 and it was surprizing peppy.
Don't under estimate the value of a fresh engine. I think its imporatnt to consider fresh engine performance vs how old and tired an engine is; before you decide to go to bigger engin and all the costly side effects from that option.
Years ago at a buddies shop, we dyno'd a series 2 with a 2.25 in it. Odo turned over at least once, and belived to be original engine and internals. 6 pulls and best peaked at 21 wheel HP.... IIRC first pull was 16 peak WHP.
Toltec Coffee Team: www.ToltecCoffee.com
'99 UZJ 100 - for glamping and grocery getting
'94 FZJ80 - our Costa Rican coffee mule
'96 FZJ80 - 3XL, racked, shaved and dipped in Raptor coat
'70 Petrol SIIA 88 - a Costa Rican expat in US on HB-1 visa
'70 Petrol SIIA 88 - for Costa Rican surf & jungle exploration
'56 Petrol S1 86 - a whole new kind of land rover hell...