Put around 200 miles on the Belvedere, 4000 stall and a cam that wont think about cleaning up until 3800+, but thats another topic. Just been breaking it in, setting valves and sorting things out. Been getting aluminum in oil filters, I found the machined valve spring pockets on my 440-1s have broken away at the thinnest part on a few valves. I have the .050 steel spring seats that came with the heads under the springs. Do I need to pull the heads and have them sent out and machined for spring cups? I am running a 1.550 diam spring. Galen

You're gonna get some aluminum for a while after installing any aluminum head but the Indy's are pretty bad. Yes, you do need to get those shims out and replace with cups. When I did that exact mod on my race car motor it all but eliminated the aluminum in my Oberg filter.

Yep
Its no secret that those cast valve pockets are a joke...
Get a aggressive aluminum Burr and grind those off flush and ad some cups

Thanks guys, I will pull her back apart. Probably not good on my oil pump eating that aluminum. I will pull it also.

when i asked indy to supply my heads machined for cups they said. 'nah nah, spring locators are the in thing, much better than cups'. those guys just dont know their sh..! of course they failed just as yours have. cups are soooo much better & control the springs harmonics better too.

i had the same problem assembled motor forgot crack pipe in eng block wont do that agein

When I pull the heads to do this repair, am I ok with Indys stainless valves? I did not upgrade to the severe duty at the time. Will any good spring cup work as long as the ID is correct and its for a 1.550 spring. If I can grind them off with a burr as Bob suggested I will do them myself. Galen

as sorry as some Indy stuff is --namely the pushrods the valves are fine--BBB in Argentina makes them and they will do fine--if a valve head ever comes off it was because something was beating on it ---those valves are fine--it is a good idea to hit the tips at the lock groove with some sandpaper BEFORE you try and pull them through the guides--they are prone to making a tiny lip there after running --NO big deal
BBB is one of the most modern valve mfg's in the world and I bet one of the biggest---pay more for valves and sleep better if you want to but no need
Yea yea others "flow " better BIG deal

Locaters are fine and the crazy cool fast stuff like your hot circle track heros ( the 9200 RPM guys ) use them vs. cups in most apps---The deal on the Indys is that where the pocket was machined it leaves a razor thin edege that SHOULD have been hit with a grinder BEFORE assembly but hey--we are talking about Indy here---

and besides the aluminum is probably from your rockers eating themselves away on the shafts
If they are aluminum--check there first