The difference is the water pump. Aluminum vs cast. You can use it if you switch out the water pump from a cast to aluminum assuming you’re not already running a 70 and later pump.
Hey, I must have been misinformed but the info I’m finding is notch down and to the front on drivers and notch down and to the rear on passenger side. Sorry for relaying bad information.
The notches face down. Down and to the back on the drivers side and down and to the front on passenger side. 15lbs on the shafts, anymore and you’ll distort them and I’ll be very hard to remove them if needed.
You should tell everyone what member blatantly sold you a butchered part that was never going to work, and more than likely sold it to you for way way more than it’s worth.