[John Milner]

I'm building a 455 for my 71 GTO and have my choice on a camshaft narrowed down between two. My car has 3:23 gears and a M20 Muncie 4 speed. No a/c, has power brakes. Just a street car that I want to sound and run good. 450 hp or something close would be my goal. The rest of my combination is as follows:

455, .030 forged flat top pistons, 9.75:1 compression
stock rods, arp bolts
stock crankshaft
6x4 heads, 1.77 valves added, ports cleaned up and bowl work done
Performer RPM or Holley SD intake (have both)
Factory ram air exhaust manifolds

I've narrowed it down between the ram air 4 cam (231 240 .470 .470 112) or the lunati voodoo (233 241 .504 .527 110)

I'm leaning towards the Lunati. Which would be the best suited for my engine?

[steve25]

Well first off you will need more then the factory RA4 cam's .470" lift if you want 450 hp with lightly reworked stock heads.
So it comes down to the factory Cam with the needed 1.65 rockers , or the Lunati Cam with 1.5 rockers.
With either Cam your gonna need the spring, push rod and rocker stud package to handle over .500" lift, and also the stock 6X valve lenght of 4.98" will not cut it either!

With a 4speed I don't think the difference between the factory Cams lobe center and the Lunati will make much difference because of your 3.23 rear gears!

[STEELCITYFIREBIRD]

Not a lot to add as far as choice..... but cam threads tend to run long.... and rather opinionated vs real world experience here. I haven't used either cam.. yet.

Factors I would consider myself:

-Rocker ratio used , and available retainer to seal clearance, would be a big factor to consider in the cam choice.

-RPM intake if you have the hood clearance, with either style carb, spread/square bore..

-Holley SD, with a spread bore carb and lack of adequate hood clearance for the RPM.(don't know how much room on those cars)

-First gear ratio in you trans would be a factor to consider also, 2.20 vs 2.56.

-Street car flat torque curve trumps peak HP.

Lots of luck!

[gtofreek]

Either cam will run fine, but my preference, of course, would be the Voodoo. I think it will be more explosive when you step on the throttle. Never been disappointed with the 704 Voodoo in a 455. Install it on a 104-106° ICL.

[AG]

I have a similar combo in my '72 LeMans convertible: 455, 8.9:1 CR, RAIV cam, 1.5 rockers, HO intake, Q-jet, and RA manifolds and it goes very well. Car does 13.4 in the 1/4 with street tires slipping off the line and a stock like converter.

[Johnny406]

I run the big Voo-Doo 60905 HFT with Rhoads V-max lifters on my bracket car with out of the box 87cc E-heads. With a tight (perhaps too) Continental converter and a 3.31 gear and a 100 shot, I went 3-1 against Hellcats last year on real street tires. Nothing against the 041, a fantastic cam in its day and still a relevant cam today but the Voo-Doo is very impressive!

[John Milner]

Thanks for the replies. My heads have BBC rocker studs so they should be fine. I'll just be running stock retainers with the crower 68404 springs. Should those work ok with the lunati camshaft? My current rockers are 1.5's.

[gtofreek]

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.

[Steve C.]

In addition to the 68404 spring being a little weak the distance from coil bind at 0.504" valve lift with the Voodoo cam may not be optimal. This presumbing a 1.600" installed height.


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[rearwheelmaniac]

Paul,

Thoughts on 1.5 rollers and the Comp 995's at 1.65" with this cam?

Originally Posted by gtofreek

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.

[steve25]

With a Cam of .527" lift you will end up with .579" lift with a 1.65 rocker.

The 995 springs coil bind at 1.020" so if you have a stock iron heads installed height of 1.60" you will have the 995 spring with .579" lift right at coil bind, not good!

If the heads installed height is at least 1.650" then you just be at the recommended.030" before coil bind height.

[rearwheelmaniac]

They will be stock heads not sure if 96 or 6x-4 yet though. thats up for debate.

I planned on using 1.5 rollers i have laying around. However I also have a set of 68404's and 995's both laying around. the 68404's are too weak to be set at 1.65" so I was asking if the 995's would be acceptable to use while set at 1.65"

Originally Posted by steve25

With a Cam of .527" lift you will end up with .579" lift with a 1.65 rocker.

The 995 springs coil bind at 1.020" so if you have a stock iron heads installed height of 1.60" you will have the 995 spring with .579" lift right at coil bind, not good!

If the heads installed height is at least 1.650" then you just be at the recommended.030" before coil bind height.

[steve25]

Wait, are you confusing 1.65 rockers with the needed 1.650" installed height I posted about?

[shaker455]

Originally Posted by John Milner

I'm building a 455 for my 71 GTO and have my choice on a camshaft narrowed down between two. My car has 3:23 gears and a M20 Muncie 4 speed. No a/c, has power brakes. Just a street car that I want to sound and run good. 450 hp or something close would be my goal. The rest of my combination is as follows:

455, .030 forged flat top pistons, 9.75:1 compression
stock rods, arp bolts
stock crankshaft
6x4 heads, 1.77 valves added, ports cleaned up and bowl work done
Performer RPM or Holley SD intake (have both)
Factory ram air exhaust manifolds

I've narrowed it down between the ram air 4 cam (231 240 .470 .470 112) or the lunati voodoo (233 241 .504 .527 110)

I'm leaning towards the Lunati. Which would be the best suited for my engine?

John,
704 cam good choice and I've used it recently.
Lunati will also grind it on a 112 LDA no extra charge which I recommend you do.
Jeff

[rearwheelmaniac]

Steve,

I was just asking if the seat pressures using 995's setup at 1.65" IH, would work with 1.5" roller rockers on the 10510704. I asking folks because I cannot seem to find a chart for the Comp Springs.

Lunati Recommends (closed 120# @ 1.65", Open 319# @ 1.1".

Originally Posted by steve25

Wait, are you confusing 1.65 rockers with the needed 1.650" installed height I posted about?

[shaker455]

I think I used the 995 with 1.5's,
I'll have to look up what I did for "IH"

[Firebob]

I run the VD 705 in my 30 over 455 at 10.7 CR with Edel RPs so it's a bit different from your setup. I also run 3.23 and M20. That cam is a little over the top for my street version. Wish I had known they would grind it on a 112 instead of the 110. I definately would've gone that route. I will say the things a beast though. And I'm sure there's a lot more in it because I'm no tuner that's for sure.

[rearwheelmaniac]

Ya know, its good to hear opinions stating pros and cons. It helps guy like me contrast whats right for my combo and whats not. My head hurt from months of cam talk and chatter. I settled on just picking one and going with it. so I ordered the 704 off the shelf. install it and see how it works for me and share that knowledge. i'll advance it to 104 as others have shared, and go from there. Mabye its a dog, mabye its a wild animal in my 455. I'm using iron heads so the next thing is whats target compression ratio. < than 9.5 or >? 6x? or 96? valve length play a role?

Yes I know ive posted on another forum as well. I dont post much, only when i'm looking for useful input.

thanks everyone.

Originally Posted by Firebob

I run the VD 705 in my 30 over 455 at 10.7 CR with Edel RPs so it's a bit different from your setup. I also run 3.23 and M20. That cam is a little over the top for my street version. Wish I had known they would grind it on a 112 instead of the 110. I definately would've gone that route. I will say the things a beast though. And I'm sure there's a lot more in it because I'm no tuner that's for sure.

[Steve C.]

Comp Cams Spring Chart

https://www.compcams.com/valve-spring-chart



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[rearwheelmaniac]

aaaand there it is. Thanks Steve.

looks like these will work. 1.650" might even be a tad stiff. Although they probably lost a little tension after sitting on the shelf for 12 years or so.
just have to go check them.

Originally Posted by Steve C.

Comp Cams Spring Chart

https://www.compcams.com/valve-spring-chart



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