fitz93z

need help, installing my lt4 heads and lt4 intake with gms intake gasket #12367777, and noticed there is a slight gap, after torquing down at the base of where the injectors go into the intake,
you can see into the intake ports of the heads,on both sides,
anybody ran into this before, should i be using a different gasket?
any help is appreciated, id like to get the car going this weekend, thanks

96capricemgr

Can you post a picture? If you can't post one can you email me one and I can post it for everyone to see.

I am envisioning two seperate but very different issues you could be having depending on what we see in a picture.

fitz93z

i can tommorow, friend has camera at moment, what are you thinking it could be?

fitz93z

heres pics of the issue

mdacton

did you get the heads milled? thats your problem...got to cut the intake it looks like

BlackDog

We need more info.
The heads look new, but the intake looks old. Was it used? If you bought it used, someone may have it milled wrong. Were the heads worked on or are they brand new?
Did you have the block worked on. Is the deck square?

We need to know what is going on, so we can give you the correct answer.
A little history will help.

fitz93z

its a rebuilt lt1 block to stock specs, no block work done, the heads where recently purchased barely used dont look like they have been worked on, trying to contact seller, intake ive had laying around dont know any history about it but looks stock to me

fitz93z

got a hold of seller of heads, they are stock, that just leaves the intake now if someone had milled it wrong, can that be fixed and how would i go about doing that, without taking the heads off hopefully?

Projectz28

hard to tell from the pic but it looks like the intake has had the top part of the mating surface milled back on an angle. The gasket surface should be flat from top to bottom. with no angles in it.

If that is the case then I bet it was done like that to try and run an LT4 intake on an LT1 head.

You have only 1 option that I can think of.... pull the intake. You can have them welded up and then milled back down to put the metal back in there.

There should be no gap. That intake will not work with a 7777 gasket. I bet it would be fine with a stock LT1 gasket though.

fitz93z

stock gasket installed seems to be fine, only start up will tell, but i think its going to work thanks for all the help, i'll let you know what happens

96capricemgr

People mistakenly believe that the LT4 intake flowed more than the LT1 intake and I think a lot of LT4 intakes were hacked up like this so they would fit LT1 heads. What you have there now is a red LT1 intake.

In machining that material off the LT4 intake every potential advantage it HAD over an LT1 intake is gone. All the LT4 intake had was more material above the port to better seal to the TALLER not raised LT4 port. That material also left room to be able to port match to the taller LT4 head ports.

Projectz28

I have to ask... if you use a stock LT1 gasket or even a regular LT4 gasket, why even have the LT4 intake? You can just use an LT1 for the same results.

96capricemgr

Well the sealing margin is thin when putting an LT1 intake on LT4 heads but it certainly has been done sucessfully.

Ideally though you would use an LT4 intake and use the extra material that was milled off this one to be able port it to better match the intake to the taller head ports.

Built LT1

There's more than one gasket for the LT4. One is for a stock intake, and the other is for a ported LT4 intake. I know this because I just used the race one to fit my new LT4 stroker.