Shimless lifter conversion....Needs Help Options

[Azncelica]

Here what I got. 3rd gen 3sgte head. Just installed new valve spring and retainer. BC brand. I know that 3rd gen comes with shim under bucket. When I order my valve spring kit, I went with retainer that will allow me to convert to shimless. Here my issue. After I measure up all my lifter, and then compare to the 1zzfe shimless bucket spec. I notices that the biggest size is not thick enough for my head. I measure all the shims like 5 times to make sure. So I know for sure that my measurement are correct. I installed all the bucket and perform a valve lash and they comes within spec. So, for sure the 1zzfe bucket are too small, even if I installed the thickest, will still be like .20mm too small. Here an example of the mesaurement I got. shim measure at 3.00mm and lifter at 2.99 add the two and you get 5.99, so to stay within spec I would need to order a 5.98mm, 1zzfe ends at 5.74mm for the thickest. I found spec on 3rd gen shims while doing to digging, found that 3.00mm and thicker shims are replacement if needed. Knowing this, 3rd gen head uses thicker shims than 2nd head. I done research and found that everyone who have a 2nd gen head, when convert over, the all comes within spec to use the 1zzfe bucket. So, after all this, I feel that I got 2 option, A- reinstalled my oem retainer back in, go back to shim under bucket, that if I can find supplier to order them. B- I was told that I would have to take my head back out and have my machine shop, shave the valve seat down to raised the valve up, inorder to convert to the 1zzfe lifter. Please, if anyone have done this conversion on 3rd gen head and run into my issue or have found a fix, let me know. Forgot, reason for shimless conversion is, I went with aftermarket cams, BC-stage 2. MAN!!!!!!!!!! Did not thinks it would be this hard to convert. All the research I've done, made it look fairly simple to convert. Thanks everyone,