Thankyou DG. it sounds like a fairly straight power curve, so I guess running it at 1500 is the right thing to do, rather than labouring it at lower revs. I will choose my pulleys accordingly, 1:1 will be perfect.
One more question, what is the oil pressure roughly?
The reason I ask, I noticed an oil pressure switch under what appears to be the oil pump housing in the cranking end below the front cover. The switch is faulty, so would like to replace it with something. Will one off a car engine be OK..... I think these switch at around 12 psi? Id like to wire this up to a warning buzzer of some sort.
And Ed, Your electric fan idea works great. Just used the one heat sensor thingy in the top of the radiator, fan cycles every few minutes then shuts down. Ill install another sensor in the bottom to share the buzzer alarm with the oil as above.