LT4 manifold on LT1
Thread Starter
Intermediate
Joined: Feb 2004
Posts: 41
Likes: 0
From: Tualatin OR
LT4 manifold on LT1
Well I was looking through the summit catalog and say that you can buy an LT4 manifold for pretty cheap considering corvette taxes. My question is or should I say questions are:
Is their any appreciable horsepower gain switching from a LT1 to a LT4 manifold on an otherwise stock LT1 motor?
Will the LT4 manifold bolt to the LT1 heads with no modifications?
I understand the LT4 does not use EGR so I assume that the LT1s EGR would have to be scraped and the PCM reprogrammed.
If I've missed anything else significant please fill me in.
Thanks,
Eric
Is their any appreciable horsepower gain switching from a LT1 to a LT4 manifold on an otherwise stock LT1 motor?
Will the LT4 manifold bolt to the LT1 heads with no modifications?
I understand the LT4 does not use EGR so I assume that the LT1s EGR would have to be scraped and the PCM reprogrammed.
If I've missed anything else significant please fill me in.
Thanks,
Eric
Le Mans Master
Joined: Jul 1999
Posts: 8,683
Likes: 6
From: Phoenix AZ
Nope, the LT4 had slightly raised runners compared to the LT1, so the intake ports on an LT4 intake will not match up properly with the intake ports on LT1 heads
EDIT: if you want a brand new, complete LT4 topend let me know, I might be able to help you out!
EDIT: if you want a brand new, complete LT4 topend let me know, I might be able to help you out!
Thread Starter
Intermediate
Joined: Feb 2004
Posts: 41
Likes: 0
From: Tualatin OR
So basically, I'd have to either port match the LT1 heads to the LT4 intake or get LT4 heads (which would lead to a cam and tuning and....) 
. I was hopin it was a possible swap for some small gains but seein as this is my daily driver I guess it isn't gonna happen soon with all the labor and parts and what not involved. Thanks for lettin me know. 
Eric
. I was hopin it was a possible swap for some small gains but seein as this is my daily driver I guess it isn't gonna happen soon with all the labor and parts and what not involved. Thanks for lettin me know. Eric
Burning Brakes
Joined: Sep 2003
Posts: 1,214
Likes: 0
From: Miami FL
Originally Posted by Zix
Nope, the LT4 had slightly raised runners compared to the LT1, so the intake ports on an LT4 intake will not match up properly with the intake ports on LT1 heads
EDIT: if you want a brand new, complete LT4 topend let me know, I might be able to help you out!
EDIT: if you want a brand new, complete LT4 topend let me know, I might be able to help you out!
I did the LT4 top end, cam......
Le Mans Master
Joined: Jul 1999
Posts: 8,683
Likes: 6
From: Phoenix AZ
Originally Posted by X-SDime
So basically, I'd have to either port match the LT1 heads to the LT4 intake or get LT4 heads (which would lead to a cam and tuning and....) . I was hopin it was a possible swap for some small gains but seein as this is my daily driver I guess it isn't gonna happen soon with all the labor and parts and what not involved. Thanks for lettin me know.
Eric
. I was hopin it was a possible swap for some small gains but seein as this is my daily driver I guess it isn't gonna happen soon with all the labor and parts and what not involved. Thanks for lettin me know. Eric
Pro
Joined: Jan 2004
Posts: 707
Likes: 0
From: Syracuse Utah
I believe the LT4 intake will only fit LT4 heads because the mating surface is machined at a different angle than any other head/intake combo. You have to do them both together or have the mating angle machined to match (probably not worth it).
Thanks again.
