Just make sure you have enough threads engaged,at least a half inch of threads--the crank snout is rather easy to strip.
I didnt use a tool to install the balancer on my 305 I put in my 79 C10 because someone had already stripped out the threads in the crank,and re tapped it to 1/2-13 thread.Since the motor was on my engine stand,I was able to wedge a peice of steel between the back of the crank and the stand,then I could hammer away without fear of destroying the thrust bearing surface on the rear main bearing.If the motor is out of the truck you can also stand it up on the bellhousing end,resting on the crank,and pound it on--its not the right way,but in the real world,its often the ONLY way!!.For the record,I have installed a few in the vehicle with a BFH,but not by choice--and I always feared it would rap when the job was done--so far so good--but use the tool if at all possible. /forums/images/graemlins/crazy.gif