Which fuel pump is correct for 1992 LS400?

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OK all you smarties, here is question that has me baffled - when replacing the fuel pump on these first gen LS400s, there are two options listed

1. The Denso, and

2. The Aisan (guatamala)

Does anyone know what the difference is, and why?  I was replacing the FP in my 1992, and not knowing any better, got the Denso from an online supplier based on their claim that it was an exact match replacement for the factory installed FP.  When I got the existing FP out, however, the construction was all metal and much more robust, with a couple of shiny bands at the base.  I did not see any branding marks on it, but noted that the Denso I replaced it with had the fuel feed nipple made of plastic, and generally appeared to be of cheaper quality (cost about $200)  Anyway, I compared prices for both the Denso and Aisan from the Lexus dealership and the prices are very different - $250 for the Denso and $360 for the Aisan (Guatamala)!!!

Can anyone on here shed any light as to why this is so?  By the way, I think that I should have got the Aisan for my LS, just based on the pictures from the dealership website show the both side by side, and comparing that to the FP I took out of my tank! $360!!!

Thanks for any insight

p.s.  For those who are wondering about the Denso - it appears to be working well, but I am concerned about its longevity, simply because of the apparent cheapness in construction.

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