[Tim john]

Looking for sound proven advice on gasket matching an original cast iron 1966 Tri Power manifold. What can I expect if I gasket match, polish or modify or a combination of the aformentioned. My original 670 cylinder heads have been enhanced by Dave @ SD Performance and flow 243 cfm, the heat exhaust cross over has also been filled. The carburetors are original & stock, un-modified in any way w/ factory jetting for a manual transmission. I have the original 3:55 safety trac as well. No A/C. Car currently runs 13.44 in the 1/4 mile in what I would consider bad air (car was running too rich that day last fall). Marcel and Dave both agree with my engine combination I should be into the upper 12's. Hydraulic Roller, H.S. roller rockers, Scat H beam forged rods, dished Ross pistons, internally balanced, ect...

My car is a 67 GTO and I do not want to seperate the water cross over on the Tri Power intake so will gasket matching be an issue when the unit is pulled up snug to the timing cover port.

Looking for a winter project here and all of your valuable advice and experiences. I could ship the intake off to SD if necessary or anywhere else for that matter but I am perfectly capable to layout, machine and modify myself for I have all the tools to do so. But if it is best to send out to someone with a flow bench I will do so. What do you guys have to say, what are your thoughts on modifying an original cast iron 1966 Tri Power intake manifold.

Thanks for sharing your thoughts guy's.

Tim john---

[67 Lamnas]

Originally Posted by Tim john

Looking for sound proven advice on gasket matching an original cast iron 1966 Tri Power manifold. What can I expect if I gasket match, polish or modify or a combination of the aformentioned. My original 670 cylinder heads have been enhanced by Dave @ SD Performance and flow 243 cfm, the heat exhaust cross over has also been filled. The carburetors are original & stock, un-modified in any way w/ factory jetting for a manual transmission. I have the original 3:55 safety trac as well. No A/C. Car currently runs 13.44 in the 1/4 mile in what I would consider bad air (car was running too rich that day last fall). Marcel and Dave both agree with my engine combination I should be into the upper 12's. Hydraulic Roller, H.S. roller rockers, Scat H beam forged rods, dished Ross pistons, internally balanced, ect...

My car is a 67 GTO and I do not want to seperate the water cross over on the Tri Power intake so will gasket matching be an issue when the unit is pulled up snug to the timing cover port.

Looking for a winter project here and all of your valuable advice and experiences. I could ship the intake off to SD if necessary or anywhere else for that matter but I am perfectly capable to layout, machine and modify myself for I have all the tools to do so. But if it is best to send out to someone with a flow bench I will do so. What do you guys have to say, what are your thoughts on modifying an original cast iron 1966 Tri Power intake manifold.

Thanks for sharing your thoughts guy's.

Tim john---

By the way your combo sounds, you would probably realize an advantage by doing some intake mods......

If you're not willing to cut-off the crossover from your factory iron intake due to value (understandable) then it probably doesn't make sense to do the mods to the runners.

If I were you, I'd get an aftermarket repop manifold and do all your mods to it, save some weight and paint in blue.....only you and your hair-dresser will know for sure.....

[Tim john]

Thanks for the feedback and belive me I have given serious thought to purchasing one of the aluminum units to modify. I am however still willing to alter my original internally but not externally.

What is the potential gain from a properly gasket matched intake manifold to cylinder head manifold. Is it RPM, Torque, H.P., Top end. A combinationof all of the above, where is the obvsious value other than knowing that it is a free swim for the air volume to swiftly make it to the combustion chamber. Can one gain 5 horse power, 10 or more ? even if one modifys the runners but then I would think you would lose velocity but gain in volume, which one is more important ? Lots of questions but little advice.

Thanks to all once again.

Tim john---

[Mr. P-Body]

TIm,

Rick Holladay's '65 GTO ragtop goes high 10s (10.91@124.5, current "best") with an iron TriPower intake and E-heads, 93 octane gas. The end carbs are "opened" as is the intake. Cross-section is equalized and the ports are "raised" to match the Ram Air IV-sized openings in the heads. I believe the combination you suggest should be capable of better than high 12s... Rick was doing 12.20s three years ago with a flat-tappet hydraulic cam and less port work than it now "sports".

For a good look at an aluminum TriPower intake "ported", go to our website and click on "Services" and then "Porting".

Jim

www.centralvirginiamachine.com

[quicksilver97ta]

I think the improvements will depend on how mis-matched the ports are to begin with. Did you stay with the original port size or open up to a RAIV gasket? The general advise to port match and remove bumps and irregularities has been around a long time as part of any DIY work on airflow as there are only improvements to be had. I had my 997's, aka 670's, professionally ported, I stayed with the original port size, and I didn't hesitate to port match my all original 66 trips intake. I felt that after spending the money on the portwork it was well worth the effort and really there was no downside to it. Sounds like a perfect winter project!

[DiamondJim]

Originally Posted by Tim john

Looking for sound proven advice on gasket matching an original cast iron 1966 Tri Power manifold. What can I expect if I gasket match, polish or modify or a combination of the aformentioned. My original 670 cylinder heads have been enhanced by Dave @ SD Performance and flow 243 cfm, the heat exhaust cross over has also been filled. The carburetors are original & stock, un-modified in any way w/ factory jetting for a manual transmission. I have the original 3:55 safety trac as well. No A/C. Car currently runs 13.44 in the 1/4 mile in what I would consider bad air (car was running too rich that day last fall). Marcel and Dave both agree with my engine combination I should be into the upper 12's. Hydraulic Roller, H.S. roller rockers, Scat H beam forged rods, dished Ross pistons, internally balanced, ect...

My car is a 67 GTO and I do not want to seperate the water cross over on the Tri Power intake so will gasket matching be an issue when the unit is pulled up snug to the timing cover port.

Looking for a winter project here and all of your valuable advice and experiences. I could ship the intake off to SD if necessary or anywhere else for that matter but I am perfectly capable to layout, machine and modify myself for I have all the tools to do so. But if it is best to send out to someone with a flow bench I will do so. What do you guys have to say, what are your thoughts on modifying an original cast iron 1966 Tri Power intake manifold.

Thanks for sharing your thoughts guy's.

Tim john---

Look elsewhere. I ran into the 11's with a cast iron 66 unmodified tripower and 6X heads, 3860 lbs. More info please, headers/convertor/tires, what is you 60'? Is your car a 400 or 455? If it is a 455 the 355's will get you there, 400 will need more gear. To start I would look at the convertor and tires. If you do decide to modify a tripower, I suggest you get your hands on an aluminum 66 and send it to CVMS along with the end carbs, I picked up over 2 tenths after mods. -Jim

[Tim john]

The cylinder heads were left alone and not opened up to Ram Air IV dimensions however I do have two Tri Power intakes and one currently is gasket matched only to Ram Air IV dimensions and the other bone stock. I was thinking of taking the second un-modified unit and working with that one to match the cylinder haeds but was looking for expected expectations and how to go about gaining them.

My concern is that I could gasket match with excellent results myself but without willing to seperate the water cross over on the original cast iron intake manifold I am wondering if the so called "gasket match" would be in vain when one snugs up the timing cover to water passage ? would this not "shift" the intake forward and mis-match my gasket match to cylinder heads ?

Tim john---

[Tim john]

Jim,

My 60' were right around 1.78 / 1.80 / 1.82 if I remember correctly. Engine is original 67 "WS" 400 cubic inch and original Muncie four speed wide ratio. The times posted were with ET slicks on stock steel rims in eight inch width heated up substantially. The car litteraly porpised out of the hole and leaped forward, caught backup to RPM's and then lurched forward. I did not have the power to carry the raised but not off the ground tires.

The car is not a race car by any stretch of the imagination, it is a very nice original appearing stock 67 GTO with the best internal components that I could afford. I did all the work myself in building (re-building) the engine, transmission, minus the internal balancing in which I had this done. Current gear is the factory original Safety Trac in 3:55 ratio.

Tim john---

[Tim john]

I forgot to mention that the exhaust manifolds are the original H.O. units flowing out through a PYPES system in 2 1/2 inch with an "X" pipe and cut outs. I am not interested in going to a tubular header, I want to keep the engine compartment looking stock (H.O. manifolds).

Tim john---

[slowbird]

I agree with DiamondJim, I would be looking elsewhere for power. One way to check the port alignment when you pull the manifold forward is to make a mark on the head where the center divider is on the intake ports and then make the same mark on the intake. When the two are aligned the marks should match up. But I would be surprised if you notice any performance difference with just a gasket match unless there is a big mismatch between the two.

[440GP69]

Jim from CVMS has Consistantly done the Best with these Tri Power's IMHO, There are other fast cars with them for sure I'm not argueing that fact, I'd either send the Iron to Jim or send an Alum Less weight=Faster and Easier to port by far andyou get the Factory look and you aren't ruining a Piece of history, Get rid of the Stock HO Manifolds put them in Storage And get RARE Oversized HO Manifolds 2.5 Outlet already Made to Fit right where your old ones sit now You don't have to change anything, The Carbs,Intake,and RARE Manifolds should let that 400 breath how it wants IMHO