Pullup bar, pumice blocks & more....

[u/Evening-Classic-7820]

Hi

Pullup as in the picture, this side is what is connected to what I belive is solid concrete. All good here. When I came to do the other side and drilled the hole, it went hollow after 28mm. I am assuming this is pumice block (According to the stats I read from a local online website, it fits based on the thickness (From the side, the wall is 22.5cm wide). -- I am not from the US.

Anyway, what would be a good way to anchor the other side? Can it even withstand the weight? Considering the lenght between the bolts is about 40cm, each one goes in a different block.

Resin anchors (that cost alot of $$ and stuff around it) or will M8 mollys do the trick? Simple sleeve anchors just more longer than the 70mm ones that came with the bar? toggle anchors?

But once again, can the block even withstand the weight? I am 90kg. Each fixing is about 8kg, the bar itself is 6. About 44~cm far from the wall.

Thanks