Seem to be #8, #10 were too big, would not even start. The #8 32 I had started but stopped a thread or 2 in. I did not have a #8 20? 24? to try
This is what the kit I bought says.
View attachment 1715945431
I don't know if the clips on my rad are OEM or not.
Clips on rad look like this.
View attachment 1715945429
The ones in the kit look like this
View attachment 1715945430
I can say one thing... Be sure the bolts are short enough, on my rad there are tubes directly under where the screws go and if they were too long they would crush / damage / pierce the tude