Rocker arms for 408 build

From a Moparts thread.
It's from 2003 but there are several bits of info I did not find elsewhere.
He references a jig for rent to drill Magnum heads for LA intakes.

Dodge Magnum Head Poop Sheet & Drilling Jig Info

ROCKER GEAR:
Stock magnum rocker arms are actually the same rocker arms as the old AMC 290-401 engine series, and are 1.6 ratio instead of the LA 1.5 ratio. To determine the valve lift with 1.6 rockers, take your LA cam's valve lift and multiply by 1.067 (1.6/1.5).
Aftermarket roller rockers are usually the same pieces as SB Chevy pieces, and may require different rocker arm studs. Some kits may include them. Most aftermarket rockers are available in 1.6 or 1.7 ratio. Small Block Ford specific roller rockers (1.6 ratio) are reported to be a better fit because of minor differences in the rocker pivot to roller tip dimensions. CAT Chevy roller rocker have been successfully used as well.

Crane: offers a stud and guide kit: PN 36655-16, which is the same part number for a Ford 5.0L conversion. The rockers PN 11746-16 (1.6 ratio) are the same rockers for 5.0L Fords and SB Chevy's. These are the same parts as the roller rocker arm kit available through MP.

COMPCams: Now offers a “real” Magnum guide plate and it is preferred over the Crane Teflon thingys. In older Comp catalogs (and possibly their website) they list a PN4842 & PN4843. These are INCORRECT. This is an Oldsmobile guide plate and it WILL NOT work properly on a Magnum head.

Crower also has Magnum roller rockers available in rail (no guide plates necessary) or non-rail (guide plates required) as well as the other necessary hardware to install them.

If you're running a moderate hydraulic cam, stock rockers are fine. If you don't have junkyard ones new ones are available from MP:
MAGNUM V8 ROCKER ARM SET
Consists of 2 rocker arms,2 pivots,2attaching
boltsand 1 guide.for use with hydraulic cams
only,production 1.6 design ratio. NOT for
4.7L V8.
MP PN 4876050 (one cyl, need qty 8 )

NOTE: Roller rocker arms WILL NOT clear the baffles inside a stock valve cover. There are several ways to fix this:

1. Buy MP cast aluminum valve covers (spendy)
2. Cut the stock baffles out.
3. Bash the baffles in with a hammer.

4. Build a valve cover spacer out of wood or metal. I ended up bolting a valve cover to a piece of wood (maple or something) trimming around it with a flush cut router bit and made myself a 1/2" spacer. Painted it good and installed it with 2 valve cover gaskets and longer bolts. No leaks so far. Small Block Chevy valve covers will even fit if you enlongate the valve cover holes a bit. I had this setup for a while, but couldn’t keep it from weeping around the top of the bolts (didn’t really try too hard though) and went with a spacer. Some SBC valve covers can be purchased without the holes drilled. You could drill your own and possibly eliminate the weeping problem I had.