As steve says it depends how you like your car to feel,on my shorty car
im using 60g down the length of the chassis but im not using my shorty right back,thats where my speedo is,again this setup wont suit everyone but it does me and all those that saw it at the 4wd regional see it works for me,the car was superb,even if i do say so myself.battery strap was for mock up only lol,i also have a 35g weight i have made that sits in the chassis kickup between the servo and bulkhead