Our GEN IV 454 is in the process of being rebuild and we have a question about the thrust plate to keep the camshaft in its place.

I did some research online and I think the GEN IV (flat tappet) does not need a thrust plate. the GEN V (with roller cams) needs a thrust plate. Both generation blocks have the mounting holes for the thrust plate, but the plate wont fit the Gen IV camshaft.

(We have a GEN IV block & cam and a GEN V block & cam. The thrust plate from the V somehow found its way into the parts of the IV, which made for a very confusing talk on the phone with the machinist trying to figure out why parts the parts didn't fit).

My Machinist thinks it would be better to modify the thrust plate so it would fit the GEN IV camshaft to keep it centered. as this is the way its done on the small block and the later generations 454.

So the question is as follows: Is this a good idea or not? I don't see any clearance issues and I think it wouldn't hurt to add it?

To be clear this is the part I'm talking about (shown on a Gen V cam):

https://ibb.co/yq4ZW5C" rel="nofollow">

Picture of the GEN IV block with cam installed and the picture showing the plate with a to small diameter hole, not fitting the cam:
https://ibb.co/8m8nWgj" rel="nofollow"> https://ibb.co/Z8wbBc0" rel="nofollow">

Cheers,
Lenny

With a flat tappet cam your distributor gear and angle of the cam lobe where it contacts the lifters keeps it from walking forward.

Thank you for the information.

Would adding the washer (after enlarging the internal diameter) help anything or rather add a failure point?

Roller cams would have the step on the front and the cam plate would be used.