Well, i just put together a R5 3600 and GTX 1070 build last week. i used a b450 mb but it came ready for 3000series. i didn't do any bios update but you need to do it for b350
CPU is currently running smooth and fluid except the quite high temps i'm getting (between 35-40°c idle/ max 90°c on load) but i'm still using the stock cooler and
going to change it some time in the future, also i never managed to reach 100% load even when doing multiple things, game running, chrome,youtube..etc very nice to have 6 cours and 12 threads
since you didn't give the exact parts you have i would extremly recomend a fast RAM for this cpu. 3200mhz is nice
after sometime of using i did some reading and most people are saying it's still early for this CPU, motherboard bioses are still beta and voltage still needs improvements since mine sits at 1.4v on idle. (because of the new 7nm die or something) overall pretty powerful processor
best of luck there mate