427 Tri-Power Input and Thoughts
Thread Starter
Heel & Toe
Joined: Mar 2007
Posts: 22
Likes: 0
From: Camarillo California
427 Tri-Power Input and Thoughts
Hello, I am rebuilding my 427 400hp motor for my 68' and want your input. It doesn't have the original heads, intake, or carb setup so want the motor to put out much more than 400 horsepower. I am going to put new aluminum ARP heads, MSD Ignition, and a better cam. I was planning on using the Edelbrock Air Gap intake and appropriate Holley Carb which would also mean I will have to go to the L88 hood.
Well, I just had a thought. Would the factory Tri-Power setup put out just as much horsepower as the Air Gap setup? Other than the fact that the setup won't be cheap. What do you guys think? If I put the Tri-Power setup on I can keep my original hood which I really like AND it's a Tripower. What do you guys think?
Well, I just had a thought. Would the factory Tri-Power setup put out just as much horsepower as the Air Gap setup? Other than the fact that the setup won't be cheap. What do you guys think? If I put the Tri-Power setup on I can keep my original hood which I really like AND it's a Tripower. What do you guys think?
Race Director
Joined: Sep 2001
Posts: 10,560
Likes: 439
From: Wellington, FL
St. Jude Donor '11 thru '25
Yes, the original factory tri-power set is very costly. I sold the one on my '67 (in good & running shape) a few years ago and got $3000 for it. However, I don't know what they go for today. 
Advanced
Joined: Mar 2008
Posts: 92
Likes: 0
If you use the 435hp manifold, the square port one rather than the stock round one you will be right there with the new heads and keep your hood. That manifold and carb set is not cheap, but it will look original and run like a bear.
Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
the tri-powered setup is definitely cool looking but it was put on the motor at the factory for "marketing" reasons, not performance. A good intake and single carb set-up will outperform the tri-power set-up (look at the L88 where they went with a single carb rather than a tri-powered).
If your goal is the MOST performance go with a single carb. If you want GOOD performance and a cool "wow" factor for shows or just visual showing off than go with the tri-powered.
If your goal is the MOST performance go with a single carb. If you want GOOD performance and a cool "wow" factor for shows or just visual showing off than go with the tri-powered.
Melting Slicks
Joined: Mar 2008
Posts: 2,336
Likes: 1
From: North Bellmore Ny
St. Jude Donor '09
The tri-power is cool looking but does require attention and the secondaries open at about 3000 rpms. It's very good for gas mileage and attention but I don't see these setups on cars for the fun factor. new they go for about $4300. I could get alot more fun for my money if that was my goal
Safety Car
Joined: Oct 1999
Posts: 4,101
Likes: 10
From: NorCal
It'll be close in a mild engine, but the 3x2 does give up flow, making up for it in sheer volume. WFO, it potentially flows almost 1200 CFM if the rest of the engine can handle it! In reality, it's probably closer to 800 actual CFM. That said, if you want all out performance, go with a large single 4V with the appropriate manifold.
My build is an LS-7 454 with the rec port tri-power and modified Stal headers and a variation on the L-88 cam. We'll see how that works and go from there. In definitely want to keep my hood.
Hans
My build is an LS-7 454 with the rec port tri-power and modified Stal headers and a variation on the L-88 cam. We'll see how that works and go from there. In definitely want to keep my hood.
Hans
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Race Director
Joined: Jan 2007
Posts: 14,948
Likes: 3,351
From: NYC NY
As has been stated over and over the Tri power has the look (and the cost for that matter) but the single 4BB will run rings around it. Why not do some research with the manifold companies? I would be willing to bet you can find a manifold the fits under the stock hood and it will only give up a very little peak horsepower over the air gap (and may even make just as much or more torque). Will you really notice 10 or maybe less peak horse power on a street car?
Pro
Joined: Aug 2006
Posts: 647
Likes: 12
From: Midwest
Hello, I am rebuilding my 427 400hp motor for my 68' and want your input. It doesn't have the original heads, intake, or carb setup so want the motor to put out much more than 400 horsepower. I am going to put new aluminum ARP heads, MSD Ignition, and a better cam. I was planning on using the Edelbrock Air Gap intake and appropriate Holley Carb which would also mean I will have to go to the L88 hood.
Well, I just had a thought. Would the factory Tri-Power setup put out just as much horsepower as the Air Gap setup? Other than the fact that the setup won't be cheap. What do you guys think? If I put the Tri-Power setup on I can keep my original hood which I really like AND it's a Tripower. What do you guys think?
Well, I just had a thought. Would the factory Tri-Power setup put out just as much horsepower as the Air Gap setup? Other than the fact that the setup won't be cheap. What do you guys think? If I put the Tri-Power setup on I can keep my original hood which I really like AND it's a Tripower. What do you guys think?
Race Director
Joined: Feb 1999
Posts: 16,978
Likes: 7
From: In Dreams There Is Truth Ohio
Drifting
Joined: Feb 2008
Posts: 1,560
Likes: 4
From: Arlington texas
I've been thinking about the Barry Grant tri power setup when I get around to replacing my engine. I like their 3 finned air cleaners better than the stock triangle. Gives it a better "wow" factor when the hood is open. I've seen dynos for tri powers as opposed to 4 barrels. They seem to go either way on power depending on the motor but they seem to be pretty similar in HP and TQ.
If it was me, I'd go tri power and be a little different. With gas prices going the way that they are and this will be a daily driver, I might not ever get mine. I'm leaning towards an LS with fuel injection for economy.
If you do it, post some pics so we can see how it fits. I'm probably changing to the same hood as you, either way.
If it was me, I'd go tri power and be a little different. With gas prices going the way that they are and this will be a daily driver, I might not ever get mine. I'm leaning towards an LS with fuel injection for economy.
If you do it, post some pics so we can see how it fits. I'm probably changing to the same hood as you, either way.
Le Mans Master
Joined: Oct 2000
Posts: 7,831
Likes: 5
From: Austin TX
That's a tough choice...
On one hand Barry is completely correct.
On the other hand if your car is a documented 400HP the correct setup
will add dollars to its value. I doubt the prices of those manifolds will
go down so it's a pretty good investment. They ain't cheap!
I'd go for the RPM and Holley myself, since you're already going
non-stock with the AFR heads (excellent choice) and stuff.
On one hand Barry is completely correct.
On the other hand if your car is a documented 400HP the correct setup
will add dollars to its value. I doubt the prices of those manifolds will
go down so it's a pretty good investment. They ain't cheap!
I'd go for the RPM and Holley myself, since you're already going
non-stock with the AFR heads (excellent choice) and stuff.
Thread Starter
Heel & Toe
Joined: Mar 2007
Posts: 22
Likes: 0
From: Camarillo California
You guys all have great input. I looked into the price of a complete Tri-power setup and it isn't cheap at all. The machine shop who is going to do all of the work plans on putting in better pistons, connecting rods, along with the ARP heads. The engine will not be stock although the car will still look stock. I am thinking that the Tri-power setup will work for me. It would look good for car shows and is something different for people to see. If we want to break it down to NASA engineering testing/specs I can deal with some horsepower loss buy not going the Air Gap single carb route. I would not need the extra horsepower for every stop light race. Thanks, Joel
Last edited by BritGreen68; Jun 19, 2008 at 05:41 PM. Reason: rephrased sentence
