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Thrust bearing behind cam timing gear (496 BBC)?

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Hi Guys -

I am building a 496 BBC and am ready to install the timing chain set. I did a lot of searching & reading on the subject of the thrust bearing that sits (or can sit) behind the cam gear, but am hoping you can confirm the direction I am going for my particular set up is ok.

Engine block is casting # 14015445, 4 bolt main. Cam is a Comp Cams hydraulic roller with a flat nose (see pic below). Timing chain cam gear is machined for a thrust bearing, but the thrust bearing did not come with the set (I think it's missing - have to call and see if it should have been included). I am using the Cloyes 9-231 Quick Button 2 piece timing cover.

Limiting forward cam thrust is accomplished with the adjustable cam button on the timing cover. My question is really about limiting rearward movement.

When I position the cam fore / aft so that the cam lobes are roughly (to the eye) centered in the lifter bores, there is roughly .135" clearance between the machined face of the engine block and the machined recess of the cam gear.

I think I should install a thrust bearing, like this: .142" Thick Roller Thrust Bearing for Chevrolet 396-454 Big Block

With that bearing installed, I can properly set the cam thrust by gently bottoming out the cam button and backing off 1/2 turn (per instructions) and also have the cam in a "centered" fore / aft position, since that thrust bearing would limit the rearward movement of the cam, once the cam button has taken up all the play.

Does that make sense and is that the right way to go about the installation? Sorry for the long winded explanation and thank you in advance for your help!

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