-Stock Toyota 2F 700lbs
-Stock Toyota Diesel even more
-Pre Vortec 350 580lbs (all iron)
-5.3 Litre (LSx style iron block/alum heads) 540lbs
-5.7 Litre (LSx all alum block/heads) 480lbs
-6 Litre (LSx iron block/alum heads) 540lbs
-366 Big Block not sure
-454 Big Block 750lbs (all iron)
*Buick GN 3.8i turboV6 430lbs
A '99+ LSx 5.3/6.0 with a factory NV4500 can be found on car-part.com. Would make for a great conversion.... They came with 4L80E's also (TH400 with OD) ....
I put nearly 20K miles on my GN powered RX-7's.... and have about 5K on my LS1 powered RX-7 now. Conversions can be very reliable if the work is done well. '00+ technology with LandCruiser style.....