http://www.toyota-4runner.org/3rd-gen-t4rs/69744-3rd-gen-faq-tutorials-documentation-reference.html
go to that section, look under the transmission section, tons of write ups and info
for me , I bypassed the radiator and mounted mine on driver side of radiator in front of ac condenser
ran all new hoses to tranny hard pipes U under ac compressor, a bit of a pain
and ran a loop between the radiator tranny ports, so if it does develop a leak, it wont leak out of radiator ( coolant)
my radiator is 15 years old, no documentation of it ever being replaced and I have all records since new (from dealer and original owner) so Im gonna replace it one of these days, not sure if Ill hook back up the tranny cooler lines to it
the advantage of a B&M cooler (that I used) according to their information and other things I have read, is it has an internal plate that allows it to bypass the lower cooling fins until the fluid heats up
have fun