got a 99 ls400 w/ a blown block due to some recent flooding in the area. the local salvage yard has a 00 gs400 engine. my question is....would the gs400 engine bolt right up and work in the ls400? both are 1uz-fe...however...both long blocks has 2 different part numbers. if it does bolt right up....then what are the differences in the 2?

 

well, the GS400 is 300HP, the LS400 is 290HP for those years.

 

so i guess the difference would be the displacement??? would it work though?

 

Displacement is the same, the HP difference is due to different intake and exhaust configurations. Same 1uzfe, both VVTI. Displacement difference would be with a 430 4.3 3uzfe.

I'd assume it would work if you switched those items off your old car (and kept the old ECU) but I'm far for an expert.