Offset valve spring retainers or keepers ?

I have some 901-16 springs going into some stock 360 heads I am messing with
The springs call for a 1.65 installed height. I can only get 1.623 installed height.
I'm not looking to machine these unless necessary. Is there an offset keeper or retainer I can use to get some more height. I would need .480 lift XE268H (max lift is .49 on these springs) at 1.62 I can only get .46
PS I'm not sinking a fortune into these heads , I am more or less practicing with them
As always thank you for bearing with my rookiness
This is what happens when I'm home 24/7