I am putting together a very budget 5.9L Magnum for my 1974 Duster 360 4-speed.
A few years ago I picked up a set of 1.92/1.62 Mopar Performance R/T heads off eBay for $550.00. They are brand new, one head is complete and the other is bare. The complete head is 'straight' Magnum intake pattern, and the bare head has been redrilled for the 'angled' LA engine intake pattern. After looking at the prices for the valves/springs to complete the second head and not wanting to ship one or the other out hastily for intake pattern drilling, I decided to put them on a shelf until I could get a better idea of what I wanted to do with them.
A while back I figured the easiest solution to the mismatching intake bolting problem was the Professional Products 'Crosswind' intake manifold. It's the Air Gap intake I wanted with dual patterns for bolting the intake manifold on. I then bought a new set of 2.02"/1.625" stainless steel valves from an eBay seller (engnbldr). I also purchased a set of Elgin RV 9908S valve springs and figured I'd have a machine shop enlarge the valve spring pads on the heads to fit the small block LA style larger diameter valve springs.

I brought the heads, valves, and springs to the machine shop yesterday. After I got home I started thinking about what retainers/locks I would have to use to make the LA springs work with the 8mm Magnum valve stems.
Will the stock LA stuff work correctly on the Magnum 8mm valves?
Is there a retainer/lock system that will work with the Magnums 8mm valve and fit my larger diameter valve springs?

My second question pertains to the large 2.02" intake valves that are being installed in these heads: Should they be deshrouded or will they be fine?

Last but not least, in the future if I decide to get one of the heads redrilled so they match (not sure which intake pattern I prefer), who performs this operation? How much is that service?

No experience with the rest of head work in this case but I will say that unless you need valves anyway I would save the money and touch up the old valves & seats. The 2.02 valves likely will not help you unless you are going to be spinning into the upper RPM range and could in fact hurt your low end. A lot of motors like the velocity rather than the volume air fuel intake.

OP said one head doesn't have valves at all.

I hope Patrick will weigh in because he has a lot of Magnum ideas. Or call Ryan at Shady Dell Speed Shop. He's a head expert and 10 minutes on the phone with him will be worth more than 20 posts here.

R.

the stems, while advertised at 8mm are actually 5/16". chrysler 2.2L/2.5L retainers work with a 1.4" OD valve spring and stock magnum keepers. otherwise any aftermarket setup for 5/16" valves will work. Hughes sells some for under $70.

watch out on installed height--magnums are notoriously short on spring installed height. my OEM magnums are only about 1.64", the R/T heads were known to be worse. a lot of LA style springs have a coil bind height of over 1.1", so you'll be very limited on max lift. the Hughes #1110 spring works very well, because it has a coil bind height of 1.040" which will give you a comfortable max lift potential of .525-.550"....

I have tried calling and e-mailing Shady Dell Speed Shop several times over the years and never once got a any form of reply.
I see Ryan's posts and always heard he is the man when it comes to small block heads.


Thanks for the info Patrick.
My springs are said to bind at 1.085"