here is the outcome of my on board air mod. remove old heater from 1974 FJ40. take 1 old cookie sheet of aluminum and fabricated into a bracket for the pump. 1 MF-1050 pump from Pep boys (got great ratings from other websites on pump speed, quality, construction, value). I matched the cookie pan bracket I made up to the bolt pattern of the pump bracket I made to the heater bolt pattern. mounted pump to bracket. bolted into place where heater was. I used the cookie pan edges as further reinforcment for the bracket to take the weight and allow the pump to purchase down onto them. now, it is within reach of the battery. on board air for under $65.00.