I basically want to know if these will fit my bike.

I have a 2006 Marin Bobcat, currently with a Truvativ X-Flow crankset. Triple. Square tampered.

https://www.bikepedia.com/QuickBike/B...rail&Type=bike

I'm going to buy these from a guy on craigslist.

https://www.performancebike.com/bikes...551_1066338_-1

Anyone foresee any issues?

Thanks.

Well, you'll need a new BB.
What are you wanting to achieve here? I can't see that you'll be getting much bang for your buck with this.

BB is included i think.

The bike operates fine. Just want to upgrade to higher quality parts.

Current cranks have riveted rings. Kind of wanted something where I could experiment with different sizes.

Bikepedia link was useless , no info, at all. 2nd picture has no indication of the condition of the used parts you are actually buying.

You have linked to an External BB type crank-set, Not a Square taper one, you need installation tools for the external thread
bearing assemblies the cups with the bearings in them, Have to get them in the frame tight and aligned.

Plus you need tools to remove your current square taper crank-set, and they are different from each other ,
so 2 sets of tools need to be bought.
Might be worth while comparing with just buying new parts installed at your LBS and used stuff with 2 sets of tools.

Or taking the Bike and the new stuff to the bike shop and paying them, Generously,
to remove the old one and install the new one, since you are not buying the parts from them.

I think this may be the option I go with.

Thanks.