What is the best source of Dwarven metal that can be converted to ingots. i know the ruins in Markarth are fairly good but i was wondering if there was any other ones i was missing with more metal t obe taken.

That one store room with the Aetherium shard.

And Im pretty sure the Court wizard in Markarth

Mzulft.
get some solid dwemer metal then duplicate it.

Radbthar, North of Whiterun is a good Dwemer Ruin for getting items to melt into Ingots at an early point in the Game. Deeper into the Ruins is not a good place for any Followers, and is full of Falmer and Automatons.

If a character is a member of the College of Winterhold, Mzulft has a very good supply of Metal to be converted to Ingots.

Markarth has a Dwemer Ruin underneath it, and the Ruin has a small quest to gain acess.

Most interior Dwemer Ruins have enough Metal to be able to build a full set of Armor and Weapons. Exterior Ruins that have Map Markers are not worth finding without Dawngaurd installed.

Almost all Dwemer Ruins have some sort of metal in them. If you're wondering which scrap metal has the higher output, Solid Dwemer Metal produces 5 ingots, but has a weight of 25. Bent Scrap Metal, Small/Large Plate metal however, yield 3 ingots, but have a weight of 2, thus making it a smarter choice for gaining more ingots.