the cheapest aftermarket LSD Ive come across is in the $250 range, a tad pricey but not entirely out of the question. Is there a good bolt in junkyard replacement thats known to work? The few rx7s at the junkyard Ive come across seem to have a much longer carrier housing than the kia, The miata is very close in total length but has the small ring and pinion like the front diff and the mazda b2200 looks like the closest fit so far, but due to the age and reliability of those trucks Ive not seen one at the wreckers with less than @140k miles.