[67gtospud]

If you don’t mind me asking, what were your other cam options? I had the 703 in my 400 for a short amount of time but ultimately decided it was too tame for me and went with the 704.

I bought my springs and retainers from Lunati and brought them to my machine shop and had them set everything up at the correct height.

[Steve C.]

If interested Comp Cams offers Camshaft Nitriding.

Nitriding is recognized by metallurgists worldwide as one of the most effective ways to increase the case hardness and lobe surface lubricity of flat tappet cams, all in an effort to enhance both break-in and long-term durability. Pro Plasma Nitriding is a patented process that uses pulsed nitrogen plasma to infuse nitrogen ions into the part – strengthening and fortifying the material on a molecular level, through a depth of approximately 0.010 of an inch. Once again, COMP Cams has proven their technological leadership by becoming the first aftermarket valve train company to own and operate a Pro Plasma Nitriding service in-house..


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[Steve C.]

More often than not calling Lunati is similar to calling Comp Cams tech. Depending on the cubicle your phone call is routed to Comp often just regurgitates the use of their 995 valve spring.
Similar to Lunati with almost all their hydraulic cams, including the Voodoo line, they say to use their 73949 valve spring.

From Jegs:

Lunati 73949 Dual Valve Springs
Seat Load: 120 lbs/in @ 1.650

From that you need to evaluate your installed height.

Some might even suggest less pressure, a low 113-115 lbs has been suggested.
That is quite a bit less compared to Paul Carters actual experience, including his dyno testing Voodoo lobes.
Regarding that low amount, Paul's response...

"They will be a little weak. You need to shoot for 125-130 lbs. on the seat, and over 300 open with the 30° intake seat. Otherwise you might experience valve bounce from the flat seat angle.
The Voodoo cam has a very gentle closing ramp, but still the 30° seat needs pressure."

And I will suggest that is probably his suggestion for a minimum and AFTER they have lost a bit of pressure with run in.

No matter what brand just remember never trust catalog stated pressures, they can and do vary. Test them at your intended installed height with the retainers you plan to use.


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[HWYSTR455]

Whichever lifters you use, get ones with removable snap rings, and disassemble & clean them.


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[455rebel]

Originally Posted by 67gtospud

If you don’t mind me asking, what were your other cam options? I had the 703 in my 400 for a short amount of time but ultimately decided it was too tame for me and went with the 704.

I bought my springs and retainers from Lunati and brought them to my machine shop and had them set everything up at the correct height.

703 or 704 , were my options. I decided 703, because of 3:15 gear, max red line of 5500(with rev limit set 5700), stock converter, daily driver, wife, daughter can drive it, non sticky tires, and I've had cars with a cam a tad too big, 1 a tad small is much more street friendly. Also, I've had a 702 in this engine, with low compression pistons, it was a beast, but run out of steam bout 4500rpm.

Now back to questions. I'm going with the Hylift Johnson. Does their R lifter make noise like Rhodes? Went to their web site and read all, but didn't say at what rpm they stop bleed down, or if they made noise? They offer a cam face hole special order?
After reading cliffs post bout all the oil going to cam, I may do nothing?
Or cut my own grove?
When the heads come off I'll question again bout springs and setup?
Still 2-3 weeks from teardown, gotta repair my son's farm tractor!

And, anyone know of a decent machine shop within 100 miles of east TN?

[Steve C.]

"max red line of 5500"

Source ?
Estimate based on previous cam ?
If from Lunati website don't put too much into it. Cam website information can be like throwing darts at a board.
Or from a similar dyno proven Pontiac combination ?

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[Jay S]

Merry Christmas!

X2 on Steve C’s post.

Lifter face oiling is only on solid lifters. Hydrualic lifters with the oiling mod have a small groove the outside of the lifter. If there is a face oiling option on a hyd lifter I have not heard of it. As cool as it would be, unfortunately, face oiling effects the hyd lifters function to much. A lot more $$$ for EMD drilling thru the face versus a groove on the outside. Outside groove usually adds $20-$30 or so, may not help much, certainly won’t hurt. More oil should be directly on the face of the lobe.

Johnson R lifter are not variable duration, not much anyway. They just have a slightly higher bleed down rate than stock so they do not pump up at high rpm. You could run them, but really do not need them unless your planning on running extended periods past 6000 rpm.

Other members have said the HS rockers fit under the stock valve covers using the 5/16 thick gaskets. It is tight. I ran crane 1.65 under stock valve covers with a solid roller cam, took some work to do that.

The 703 really does not have much more rpm potential than a 702. It has more overlap and more lift. But the intake closing and the exhaust opening are within a couple degrees of each other between those two cams. 703 will make more hp than a 702, but at about the same peak rpm. A couple hundred rpm higher for the 703 over the 702 would be about it. It will be a beast in the midrange though in a 455. At 5700 it will sound like the 455 with the 703 is going to come thru the hood.

[455rebel]

Originally Posted by Steve C.

"max red line of 5500"

Source ?
Estimate based on previous cam ?
If from Lunati website don't put too much into it. Cam website information can be like throwing darts at a board.
Or from a similar dyno proven Pontiac combination ?

.

My reasoning is stock resized rods with ARP fasteners!

[Steve C.]

My point was that the combination may not make its peak power at 5500 rpm. Not the ability to "rev it" to that or a higher rpm.

For information only:
Crower Part Number: 66056X3-16
Hydraulic Lifters CamSaver Pont & Olds V8

Regarding valve springs if it were me I'd look at PAC Racing or K-Motion for a suitable spring for adequate pressure with the Voodoo lobe.


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[pastry_chef]

Dyno with a 703
http://forums.maxperformanceinc.com/...d.php?t=776169

[455rebel]

Originally Posted by pastry_chef

Dyno with a 703
http://forums.maxperformanceinc.com/...d.php?t=776169

That looks nice!
If I opted for the 704? Would the off idle tq, still be in the 400s?
Would I gain more than 20 HP @ or below 5500rpm?
It ant too late, I ant ordered it yet!
Also the 704 has lift over .500, would that add extra work to the heads and train?
I'm getting the impression the 704, in most opinion, is still a smallish cam?

Also I've emailed https://www.ionbond.com/about-ionbon...locations/usa/, for a quote on coating? I'll post results?

[67gtospud]

Originally Posted by 455rebel

That looks nice!
If I opted for the 704? Would the off idle tq, still be in the 400s?
Would I gain more than 20 HP @ or below 5500rpm?
It ant too late, I ant ordered it yet!
Also the 704 has lift over .500, would that add extra work to the heads and train?
I'm getting the impression the 704, in most opinion, is still a smallish cam?

Also I've emailed https://www.ionbond.com/about-ionbon...locations/usa/, for a quote on coating? I'll post results?

I cant say what your numbers will be vs the 703 but will say that when I was running the 704 cam in my otherwise stock 400 it pulled very hard off-idle and had excellent street mannors.

[pastry_chef]

Originally Posted by 67gtospud

when I was running the 704 cam in my otherwise stock 400 it pulled very hard off-idle

manual trans or auto with stock converter?

[67gtospud]

Originally Posted by pastry_chef

manual trans or auto with stock converter?

Manual trans

[1968GTO421]

Originally Posted by 455rebel

And, anyone know of a decent machine shop within 100 miles of east TN?

Don't know of any shops close by. Used to be some really good machinists in Asheville in the downtown area in the '50's-'60's but they were all run off when Asheville went "tourist town"

Best I know of is Wayne Sless in Greenwood, SC. He did the engine for 64Speed here and for Caster1 who is on here. I talked with Caster1 whose engine was done in Dec 2018 and he is still very happy with it and no issues.

Here are some links to Caster1's build along with a map link.

http://forums.maxperformanceinc.com/...86#post5973886

https://www.youtube.com/watch?v=0D6C...ature=youtu.be

https://www.facebook.com/pages/Green...43307355715592

https://www.google.com/maps/dir/John...3!2d34.1954001

Rebel, Best of luck to you no matter what you decide on machinist. I,too, am deciding between 703 and 704