camshaft thrust button

I did a google search and did not find a thread so I'll ask my question here.
I am rebuilding a 225 and have had to go thru three timing covers due to old and broken bolts and cracked housings. None of the three had a camshaft thrust button. I can only find it listed for a 231 and the machinist at RPM machine said that it is necessairy to have one.
From the pictures at Rockauto it appears to fit inside a hole in the end of the cam. My cam is female threaded for the distributor gear and fuel pump eccentric.
Does the 225 oddfire use a camshaft thrust button and if so is it the same as the 231? Exactly how does it fit?
Thanks,
Tommy

 

That link doesn't take you anywhere.

 

Advanced Auto parts sells the thrust button and the spring it attaches to. there is a listing for the 225. It sort of clips to the front of the cam when the gear is in place, easy to see when you have it all together. also look at a FSM to show you the relationship.

 

Did anyone ever find a part number...

The closest I have found is this, but it says it does not fit my engine... Sure looks like it should though..
Advance Auto Parts - Down for Maintenance

This little part is such a pain in the backside to find...

 

Yes factory button is plastic not metal.
Try oldbuickparts.com

 

Interesting I had two blocks at one point and I recall the other one had the button and spring (lost it of course), that was metal. Could of been the wrong one I suppose...

 

TA Performance has the cam button kit. $15 from what I believe I remember seeing on the quote. Its literally a spring that clips onto the head of the cam sprocket retaining bolt with a plastic button head on the opposite side of the spring.

 

Yup, They just got back to me this morning.. I ordered it up!!

Local Engine Rebuilder Supply shop said they had one... $10 later its for the later model, the spring wouldn't fit over the cam bolt...