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LT4 LT4: matching intake manifold ports to intake gasket - comments?

1996 LT4 Topic

LT4man

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I have to replace my intake manifold gaskets. A little seepage at the rear.

While I have my intake off, I was thinking of doing what Jim Mason (Grand Sport fame) has done. The idea is this could be beneficial to a slightly modded LT4.

http://www.hashmarks.com/techtips/intake_porting/intake_porting.htm

This would be the ideal time to do this.

Anyone have any thoughts or tips?

SAVE THE :w
 
S

stgry1

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I think you got the most info on the CF. You may get some here but not nearly as much traffic.
 

froggy47

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I would do it so long as you're there. No down side that I know.
 

Hrtbeat1

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Gregory

I've been collecting parts to mod out a LT4, so I can keep the original, well, original. One of the parts I aquired was a LT4 intake that needed powdercoating. I had the gaskets to match so I lined them up. There is quite a difference. I ported out around the injector openings to just shy of the gasket marks. It looks like it will help a lot. I haven't installed it yet but I've got some pictures I'll post up when I get a chance.

:w
 

froggy47

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Gregory

I've been collecting parts to mod out a LT4, so I can keep the original, well, original. One of the parts I aquired was a LT4 intake that needed powdercoating. I had the gaskets to match so I likned them up. There is quite a difference. I ported out around the injector openings to just shy of the gasket marks. It looks like it will help a lot. I haven't installed it yet but I've got some pictures I'll post up when I get a chance.

:w

I have heard that there are 2 types of gaskets, standard & "off road".
 

Hrtbeat1

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Yes there are ... the standard production gasket and the 7777 gasket. The standard leaves some of the intake shrouded from what I've heard. The 7777 gasket matches very closely to the intake openings on the heads. BTW the 7777 gasket is sold in singles so if you order them be sure to get 2.

:w
 

froggy47

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Yes there are ... the standard production gasket and the 7777 gasket. The standard leaves some of the intake shrouded from what I've heard. The 7777 gasket matches very closely to the intake openings on the heads. BTW the 7777 gasket is sold in singles so if you order them be sure to get 2.

:w

That looks like a "healthy" difference. Did you quantify the performance gain? Or done along w/ other mods?
 

Hrtbeat1

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I haven't totally completed yet ... waiting on powdercoating. I had planned doing this along with a cam change, but it would be nice to know what each mod actually added. Then again they all kinda work together.

:w
 

froggy47

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Depending on the cam, I think you are going to be a very happy camper with these mods.

Going to do edits to the computer?
 

LT4man

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Gerald,

I am still on the fence about this project. I have been driving my Vette for the past week. The darn car is so fast and idles so well...................

I just don't know if I will realize any improvement. Brian at pcmforless did my tune about two years ago. After I had done all my other mods. Brian got the darn thing so dialed in!

Your pics are so clear. Lots of material in the way of the flow. No doubt!

Well, I am not going to do this for another couple of weeks. Plenty of time to think and change my mind! :L Several times! ;LOL

SAVE THE :w
 

Hrtbeat1

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Depending on the cam, I think you are going to be a very happy camper with these mods.

Going to do edits to the computer?


My cam is the TPIS ZZ409 226/226 .555/.555 w/ 1.6 rockers.

Yes I am doing all the computer mods myself.

:w
 
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Its all about flow!
All you have to begin with is a big air pump, get it in and get it out smoother and easier.
Might as well go ahead and yank those heads and do the intake and exhaust. Port match them to the gaskets, slick those babys up and go like a bat out of .....Hello, are you getting this? :L
Thats been done to the Jeep, the 77, and the 71 is being done this winter.
 

Hrtbeat1

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Oh Yea I get it. I was planning on using set of AFR 195 LT4 Eliminator heads when I do the rest of the build. Those puppies flow. With the cam and intake done it should make some decent power.

:w
 
Joined
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1985 Coupe /1977 L82 Coupe / 1971 Red Coupe
Oh Yea I get it. I was planning on using set of AFR 195 LT4 Eliminator heads when I do the rest of the build. Those puppies flow. With the cam and intake done it should make some decent power.

:w


It should be a rocket!
 

froggy47

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Would you mind posting a thread on the computer edit you do?
 

Hrtbeat1

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Sure but I think I'll start a new thread. Just got my data logger and gotta' figure it out first. :L

:w
 

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