poly lock rocker arm nuts
 

I think my crimp nuts are coming loose, as they have been backed off and retightened a few times in my attempts to properly lash the valves.
I am looking to get poly lock nuts for the 7/16 studs on my 455 HO.

Will I still be able to use the factory oil drippers, and if not, how important are they?

Also, Crower nuts are a lot lower price than Mr, Gasket, etc, ($38 vs $64).
Is there any reason not to use the Crower ones?
Thanks!

"...Crower nuts are a lot lower price than Mr, Gasket, etc, ($38 vs $64).
Is there any reason not to use the Crower ones?..."

Haven't read any bad reviews of the cheap Chinese poly-locks. Back in the old days I used Mr. G. But nowadays, there are lots of brands cheaper than Mr. G.

CC has some cheap ones.

https://www.summitracing.com/parts/c...RoCOowQAvD_BwE

http://www.jegs.com/i/Comp-Cams/249/...RoC_OsQAvD_BwE

https://www.ebay.com/itm/COMP-CAMS-4...4383.l4275.c10

Great. I will get the cheaper ones.
Can the oil dripper rail be retained with poly lock nuts?

I've used oil drippers before with poly locks. Usually I double gasket the valve covers for clearance.
Oil drippers aren't really a necessity anyway. GM went away with those on most engines in late 60's and early 70's, not to mention most people back then were hotrodding with aftermarket covers, and none of those have drippers either.
I have several examples here running without the drippers for many years using full roller setups and ball/socket setups. So if you feel the need to remove them, it's not an issue.

you will probably have to bend them flatter so they don't hit the taller poly locks...I did

Or space them up using thick washer's on the attaching studs
 

I've done that a couple times to get extra clearance.

Poly locks are always good.

Yeah. Crimp nuts are only made to be used once. You can go the cheap route and re-crimp them by crushing in a vise, or smacking them with hammer on anvil. Not fancy but it works.

The crimp nuts are so cheap that I typically just buy a new set if I have to do much adjusting.