Questions concerning a Tunnel Ram Intake

[Paladin]

Would really appreciate some input from those more knowledgeable than myself (that's an easy task) !
A few years ago I built my first engine ever, took a Mark IV 454 4bolt block and bored it 60 over making a 468. It took me about 2 years of researching this project and figuring out what would work with what and what wouldn't, then about another year collecting up all the parts together. I wanted everything there when I started so I didn't have to keep stopping and waiting for another piece of the puzzle to arrive. Well, luckily I didn't wind up with a 6000.00 paper weight, it screamed out of the Hookers while sitting in the engine stand I built. Now I have this wild idea of changing out the intake manifold and installing a tunnel ram with 2 nice big holleys on top. Bigger is better, right?
I love the attention my dually receives rumbling down the street with the shotgun scoop sticking out the hood but now I want to go for the "Oh my GOD" effect!!! Quess I'm a bit of a show off as the little lady says but I'm also old and I've earned that right if I want. Plus may as well spend the money on something I want instead of saving it for the kids to waste after I croak!
My questions would include, what type of HP change could I possibly expect if any, what other things must I take into consideration, would I need to change out any internals, etc.
I have also toyed with the idea of nitrous! Here's a couple pics of my current setup! Any thoughts or ideas and recommendations will be greatly appreciated!!

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[Shorty81]

Beautiful Chevrolet Mike !!! That big block is full on EYE CANDY !!! I like what you are doing, but not a fan of nitrous.

 

[shiftpro]

Beautiful truck Mike. Something about huge blue trucks haha.
You rig already has lots of "Oh MY God" effect, for sure

Tunnel rams are about high rpm power. They can not produce torque unless... I'll get back to that in a moment.
The gasoline in that much space (inside the tunnel ram) will begin to go back into liquid from it's air/fuel gaseous state. So there goes your idle as well.
You would have to change your cam as well, for something with a lot of duration and little overlap. And you would need at least 781 heads to get enough flow to feel it. Actually you could use square ports as these again like the tunnel ram, begin to really produce power over 3500 rpm.
So for any type of street power, or truck power (torque) the tunnel intake will only set you back.

Now if your running propane, my favorite high octane clean fuel, the tunnel ram would be fine. You would need two
mixers (carbs, like Impco 425s) and two regulators also called evaporators and a fuel shutoff valve, electric or vacuum. Oh and lots of compression, 10.1 at least. THAT's where you get power!

Nitrous...? Steel crank for sure. Need a heavy wallet.
Yes you can run nitrous with propane, just saying.

I realize you're not about to switch to 'pane, just sharing what I know and that high rise type of intakes work just fine with a fuel that remains in gaseous state. Very popular in Australia...

 

[Paladin]

Beautiful truck Mike. Something about huge blue trucks haha.
You rig already has lots of "Oh MY God" effect, for sure

Tunnel rams are about high rpm power. They can not produce torque unless...
You would have to change your cam as well, for something with a lot of duration and little overlap. And you would need at least 781 heads to get enough flow to feel it. Actually you could use square ports as these again like the tunnel ram, begin to really produce power over 3500 rpm.

Thank you shiftpro, yeah it does resemble someone's avatar! LOL Here's a few more pics to show some of what is already there to work with. Already have the 781's , some Eagle "SIR" 5140 I Beam connecting rods, and Probe Forged Sportsman Race Series pistons!

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[HotRodPC]

Great looking truck, but without going much into detail that it looks like @shiftpro may have already done, my response is, NO !!! Tunnel Rams usually don't even start to think about making any kind of power until at least 4000-5000 rpm. In short, they're just not really streetable and need a huge ass cam. IMO, it would be all show and no go for this build.

 

[bucket]

I'm very intrigued by this propane/tunnel ram combo. So it will still be capable of low end grunt? I suppose long distance travel would be difficult and probably out of the question?

 

[legopnuematic]

I'm very intrigued by this propane/tunnel ram combo. So it will still be capable of low end grunt? I suppose long distance travel would be difficult and probably out of the question?

Just strap one of these in the bed. Problem solved.

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[HotRodPC]

Just strap one of these in the bed. Problem solved.

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Now you just need a trailer to tow the fuel tank and a long hose to the intake. Ready to roll.

 

[shiftpro]

I'm very intrigued by this propane/tunnel ram combo. So it will still be capable of low end grunt? I suppose long distance travel would be difficult and probably out of the question?

From what I've read they are popular in Australia. You should get all the benefits of the intake but not the loss of bottom end, which happens with gasoline because at low rpms... the fuel/air mixture becomes gasoline rain.
I do know for a fact that any single plane type of intake works wonders. As liquid pane turns to gas it just keeps expanding. The better the heads flow the better pane works. Increasing efficiency and power does not negatively effect economy... unless of course you are using this new found grunt.
Look closely and you can see the size of the tank in Big Blue my avatar. And whoosh there we just passed another pane fill location and nope we're not stopping. Pane tank come in all sizes. And in Canada, EVERY house you pass has a propane barbecue in the back yard hehe.

Oh and did you know that with pane fuel you can smoothly idle down to 450-500 rpms?
Tear down any old engine that has been on pane for most of it's life and you just will not believe how sludge free it is inside.

 

[shiftpro]

Thank you shiftpro, yeah it does resemble someone's avatar! LOL Here's a few more pics to show some of what is already there to work with. Already have the 781's , some Eagle "SIR" 5140 I Beam connecting rods, and Probe Forged Sportsman Race Series pistons!

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Wow nice deck height! Almost looks like slightly over deck..? Crush the gasket and .020 squish... yeah baby!

 

[shiftpro]

Thank you shiftpro, yeah it does resemble someone's avatar! LOL Here's a few more pics to show some of what is already there to work with. Already have the 781's , some Eagle "SIR" 5140 I Beam connecting rods, and Probe Forged Sportsman Race Series pistons!

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How many miles on the roller cam by now?
Looks like the same pistons I have for my 496 build. What's your compression ratio at?
What's your fuel economy sitting at?