I designed this for my raspberry pi 4 with passive cooling case from geekworm:

https://www.amazon.de/gp/product/B07VD5L1VY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

as the holes are same distance it should also work for other pi versions. the pins are as slim as possible so maybe even suitable for other cases too.

If you want to fix it better to the pegboard use my TPU clips: https://makerworld.com/en/models/47195#profileId-48898

Necessary hardware:

4 M2.5x18mm countersunk screw (see attached picture)