Aluminum flywheels use a 'steel' ring gear - same as iron/steel flywheels - for starter driven teethRyan
... something to consider is that your starter gear has hardened steel teeth that will be engaging aluminum, which is a softer metal. You may need to be careful with that.
Many of the 80's ~ 90's 305/350's in both passenger and light truck applications used a cast aluminum flywheel for the weight savings.
They are NOT high RPM rated units and not recommended for most performance applications :noway:
Check the balance type used also - even if your application permits, they may require changing your crank/damper balance system to use ...
Better to buy a new and rated flywheel that meets your needs than try to 'junk-yard' source these :yes:
If your planning any drag racing a slightly heavier unit may help your times - if your planning any track/road course driving then a lighter unit may best fit your needs ...