Modern graphic cards (ie: GeForce 4070 etc) are HUGE and heavy!   Typically only well supported at the rear of the card where it is secured to the back of the case.  This can put a LOT of strain on the PCI slot and the card can eventually sag and potentially damage your motherboard.  You can buy braces like this on Amazon for about $10, but why do that…just make your own!  :D  

This is adjustable from 70mm to 110mm in height.  Several versions of the base.  The one I made for myself has a pocket for a 15x5 magnet (as shown in pic).  There are a few other included GPU_Base options for other common magnets, and one without any pocket for magnets if that's your preference.

I printed in PLA+, should be fine…tons of fans in my case, but if you're worried about heat, could definitely print in PETG.  I have a Bambu X1C and it's pretty dialed in so my tolerances are pretty good in regard to the threads.  If you're having trouble with screwing the threaded parts to adjust it (too tight), perhaps rescale the threaded insert portion DOWN a tiny bit.

Only need to print 3 pieces.  One of the bases, one of the threaded_inserts and one nut.  I printed at 0.16 layer height…I feel that threaded components work a bit better if the layers are a bit smaller myself.  All can be oriented on the print bed to be printed w/o any support.

At any rate…works GREAT for me, hope it helps someone else!