MP magnum R/T heads

[waynebo]

Mancinni is moving out the r/t heads so i bought a set but have found valves and springs to be pretty limited,anyone on here have experience with the magnum heads as far as valve's and springs and what is the max lift from said combo?

Mopar list a spring with zero details that says good to .600" lift yet is the installed height and retainer guide clearance even machineable to achive this said lift?It appears to me a longer valve will be required to do much more than a mild street ride..Its looking like i will have to pay up and have the guides enlarged to 11/32" and a valve job done on my new heads even though they have a great v.j...Mopar can do some stupid sh t.
Wayne

[3404spdvaliant]

Who cares about .600 sb on the street anyway.
Just cut the guides down for retainer clearance as for the springs
pop up retainers & cutting spring pads should fix any installed height issues.
Mopar who is I think the only one to make 2.02 8mm stem valves or at least were when I bought them a while back $18 each, so like another guy saidyou could put cheap chevy11/32 valve stem & guides in but I think that would end up costing more money over all.
That factory vj is bitchin huh
and outta the box the short turn..... awesome besides below seat machine angles.
Your going to find a alot of power with those heads if you clean'em up a lil.

[waynebo]

Yea i hate too have the v.j touched so i will probally go with the stock 8mm valve size as they are lighter,maybe some behives and titanium retainers.
The cheaper and easier to find chivy rocker arms is what i like about the heads,prefer the mopar shaft but chivy is plentiful and cheeeeaaap.

[waynebo]

Sanborn don't you have experience with magnum heads?

[3404spdvaliant]

I'm beginning to think know one else has fooled with them or even seen the
bitchin ports of these heads witch is a shame.
I would be running these on my 408 in progress if it weren't for the pedestal
rocker,yes i can't get past that part maybe some day, I mean it's like your wife saying we can have a threesome but it turns out it's another dude.

[N.R.F.D.]

lol yep true

[waynebo]

http://i116.photobucket.com/albums/o...bofirst/rt.jpg

R/T and W2's,which one too keep.

[3404spdvaliant]

You can get big numbers out of RTs but even bigger with the W2s.
So what cubes, cam range, gear.
With a 318 RTs would have a hair more velocity than W2s but with gear
who cares about a hair more velocity.
With 340-360 either head will let them breathe with the W2 making more
peak high rpm power.
So what are you doing with them and what motor?
It's true the RTs have really good/best low lift flow of any head out there
there fore making them the better choice for stock cube w/stock to.540 lift, basically idle -6800 though you could rev more and do more with them if modified further.
But if you get in to .520+lift & 4.10+ gear with the W2s velocity is a memory that will soon be forgotten.
So what cha doing with em?

[waynebo]

Will be going on a 360 in a 77 gremlin,strip duty only.1/8 mile 4.56 or 5.13 depending on the rear end i use,9.25" or 8 3/4" kb 107's pistons with a engle kv-3 i beleive,around .600" lift with 1.6 rockers.If i run the r/t's i will probally run a tunnel ram if the w2's will be a holley strip dominator.Converter is a t/a 38-4000 stall.Also have a GER 4800 .
Main thing i gotta get time to do the car,its going to be a get it going and then fix it up as i go,i wanna get on the track.

NOW http://i116.photobucket.com/albums/o...t/PICT0066.jpg

Future http://i116.photobucket.com/albums/o...MC-Gremlin.jpg

[3404spdvaliant]

Run the W2s.
Are these the econo 810#W2s?
If their not the econo's then they will cost a little more than econo's for valve train but will flow more than the RTs especially .550&up lift

[waynebo]

http://i116.photobucket.com/albums/o...w2chambe8r.jpg
No there race w2's,i have everything except pushrods,may see them on ebay this week,wayne

[3404spdvaliant]

Originally Posted by waynebo

http://i116.photobucket.com/albums/o...w2chambe8r.jpg
No there race w2's,i have everything except pushrods,may see them on ebay this week,wayne

Already have the rocker gear
Killer!!

[kick_the_reverb]

Strip car? no question about it W-2. They are the closed chamber ones, you have most of the parts, what's not to like better about them?
Have fun,
Ran

[rumblefish360]

Heres my bitch about Magnum heads, though I like'em, the valve train under hairy performance levels is not typical old school MoPar strong.

Who makes a stud girrdle for those heads to stiffin it up?

I'd go W-2. Then a solid roller.

[waynebo]

I agree 100% on the rocker gear for the mags but at least when you do break one there everywhere as far as replacements, and i'm not in the best of health so i can have plenty of fun with the r/t's.I must admit i love the combustion chamber on the w2's way more.you can see how the intake side of the chamber is shaped too improve intake flow and the exhaust when everything is being forced to the combustion chamber will be funnelled right on out,so the chamber is a h.p maker in its self,wayne
p.s grimlins are pretty light,i believe around 2650-2700 lbs

[waynebo]

good site to compare heads''' http://www.shadydellspeedshop.com/moparheads.htm

[3404spdvaliant]

Those guy's know how to port heads been a while since I checked them out.
Right on!