cooling- 2 row rad, a cpl high flow cooling fans and decent coolant and maybe some water wetter and you should be fine, if your doing ALOT of track days look into a oil cooler... my car had the tendency in 90 degree weather to run WAY hot so i had to do alot of cool downs so i couldn't hot lap all the time .
cluster- if your using a DOHC cluster make sure you install a DOHC temp sending unit for the GAUGE not ecu.. the gauge sending unit is the single blade sensor located on the intake manifold at the front. Tach wont work, i never got mine to with all the little trick everybody says should work... i just picked up a modded DOHC from raw brokerage
BBT RB Tachometer Conversion - Nissan 240sx - Raw Brokerage - Your #1 source for RB20 / RB25 / RB26 parts!
tach works perfect now
chris