You'll probably have to go junkyard dogging for em. The harmonic balancer has the pulley groove made into them. So you will have to find a doubble grooved balancer and water pump pulley at least. They are out there. I found a set off a mid 60's chevy C-10 when I was looking for a replacement balancer. However the water pump pulley had a different mounting bolt pattern than my original single groove pulley. So there is also a pump difference as well. Some have a dual pattern and some don't. Mine didn't. Some later model 6 cyls had a seperate 3rd groove pulley that bolted on the balancer. I found one off an early 80's C10. I even scored the old school aftermarket compressor brackets for a saden style compressor off that same truck. So look around at later model 70's- 80's 6 cyls. The pullies should interchange with the earlier engines.