recon engines are a minefield, its an area that really needs to have tougher legislation..
as an example..
lets say the remanufacturer have an engine that has done 100k miles, with knackered big end bearings..
that company can strip the engine, re profile the crank and fit new bearings, put it all back together and sell it as a fully reconditioned engine...in other words, you buy an engine believing everything is as new, but in reality you have an engine with lovely new big end bearings and a good crank...what you dont get told is everything else has done 100k miles..
you need to find someone highly recommended..ignore the advertising blurb.
a properly re manufactured engine will cost nearly as much as brand new...so when you get quoted 500 for a recon engine, that would cost 2k new, can guarantee only some of that engine is recon...you get what you pay for despite all the claims.
9 times out of 10, the guarantee given with that engine isnt worth the paper its written on.
in 30 years, i have come across far too many problems with recons, i refuse to use them myself, so if any customer insists on me fitting one they either pay far more to have myself fully recon the lump, or they have to supply it and i will only guarantee the fitting NOT the engine itself.
if i was you, i would either do serious research for a reputable firm, or go for 2nd hand