Anyone know the differences in a 1967 V8- curved pitman arm with power steering and the 1967 v8- curved one without power steering?

The one I took off has casting #9789158
The Rare Parts replacement is 1/4 inch shorter than the old one.
So I'm trying to figure out which one is correct

1973 Numeric Parts Index says:

1967 Firebird 8 cylinder power steering: 9789157
1967 Firebird 8 cylinder manual steering: 9789156

Thanks
I'm looking at vikki's site under 73 index and only see "group numbers". Where did you find these part numbers?

You find group number then use the Parts index to look up the group number. http://thefirstgensite.com/html/partsindex.html

Harold-

Looks like you posted about the same number pitman arm. https://firstgenfirebird.org/forums/ubbthreads.php?ubb=showflat&Number=266543&page=1

What conclusion did you come up with about your pitman?

No conclusion. I did not know how good the joint was so I replaced it with the 67-68 powersteering pitman arm that ames performance sells and it works fine.

I thought there were only a straight (non power) and curved (power). I was not aware of multiple curved ones.

Your new pitman arm have "RP" cast into it?

Rare parts shows 2 different arms for v8 cars
So does classic industries http://www.classicindustries.com/shop/1967/firebird/parts/steering/pitman-arms/

Not sure why Ames only lists one arm

I believe all these companies are reselling the Rare Parts pitman arms
I also think both these arms are built almost identical, so maybe that's why some businesses only list 1 v8 pitman arm.

Going to do some measurements tomorrow

My conclusion-

I believe the non power V8 cured pitman arm has a much smaller spline hole to mount to the gear box.
I also think there's a slight difference in length

Here's my measurements-
Original Cast 9789158 (A GMT1)
Spline tapered hole = 1.178- 1.220 inches
Center spline to stud = approx 5.75 inches

Rare parts #20798 (V8 with power steering)
Spline tapered hole= 1.175- 1.220 inches
Center spline to stud= approx 5.50 inches

Rare parts #20761 (V8 without power steering)
Spline hole= 1.028 inches (according to manufacturer)
Center spline to stud= 5.663 inches (according to manufacturer)

The non power arm (#20761) appears to be closer to the 9789158 length, but the power arm (#20798) seems to be correct spline hole diameter...
I gave up and just installed the [censored] thing (#20798) with hopes that if someday this bird is drivable, I'll mess with it then if it's even an issue.....

One last thought- Why is number 9789158 not a correct part number? Is it because it's a cast number and not a official part number??

That's what it says in the ad for the arm for sale on EPay atm...

" GM Part # 9789156
Group # 6.859
Casting # 9789158 "