302 harmonic balancer

Your 68 302 is a 28oz balance.ford started using the 50oz balance around 1980,so everything before that is 28oz.Yes the flexpalte and balancer need to be matched,both 28oz or both 50 oz,etc.Is the engine still out of car?You can look at the flexplate/flywheel for the wieght welded or cast in.A 28oz is a short weight,about 2 inches long,a 50oz weight is easily twicw as long and rectangle in shape,a 28oz is more square shaped.This should also be evident on the backside of the balancer.Ford had so many different balancers and pulley choices that it's tough to know what you have.The 3 bolt crank pulleys were mainly used in the 60's and early 70's and then ford switched to the 4 bolt pulley like around 1973 or so.What are you putting the engine in?New stock balancers are pretty cheap likw $50-60 bucks,If I were you I would probably just buy a new one for your cars application so you get the right one for your pulley alignment.

I really wouldn't be switching it to 50oz if your not sure what crank is in engine or if it had been balanced at machine shop for 28oz balance.Assuming engine was rebuilt using a stock crank or if original crank was recut,you need to leave it 28oz unless told otherwise by guy you got engine from or the machine shop that did work.You can't swap balance weights because crank is also a determining factor.Weighing the balancers might not give you a clear cut answer,you need to know what/where they came from.You really need to talk to whoever you got the engine from.

Yes you can,just remove the oil pan and you have to look for the numbers.It will be there somewhere on the crank.Ahhh,a stoner.....