Intake manifold dilemma

[nibs]

Hey guys, so Im in a bit of a tough decision right now and I thought maybe some of you could shine some knowledge or advice my way so I can make the better choice of the two...

Im in the process of getting my LQ9 ready for install into my truck and Im at the point to where Im getting all the small things finished up and slating out my purchases. I have a complete LQ9 from an Escalade that I recently bought from a friend of my father in law. Im not going to tear it apart because it is in running condition, so there is no real need to. Prior to buying this engine, I already had a few parts in my garage including 243(LS2) heads, LS2 intake manifold, and a nice new cam. When I acquired the new engine, it came with a GM performance 4 bbl style manifold.

To be honest, I cant decide which intake manifold to use! Im planning on running the MSD AtomicEFI system, and they arent making it any easier to make my decision... They make a system that is a carb style replacement and they also make a setup that has the fuel rails that works with the traditional LS manifolds.

I like the 4bbl style manifold for its classic looks, and the different style than alot of people have done with LS swaps. The negative side that Im worried about is the killer of low end power that they are...

Does anyone have any thoughts to add to my Pro/Con list? I would really appreciate your help!

[Jon01]

What are the specs on the cam you have?

[nibs]

here ya go! IM shooting for around 425 WHP with this truck

[nibs]

oh yea, here is a pic of the engine with the manifold of question. I know everyone loves pictures!

[Jon01]

Is the intake a dual or single plane unit?
Auto or manual trans?

IDK that that cam will get you where you want to be powerwise. If the intake is a dual plane unit I'd be looking at it real hard too.
What I would do is sell the cam, carb & LS2 intake, stick the 243's on there and pick up a used FAST 90/92, MS3ish cam and run an OEM controller vs. the MSD stuff.
With the 243's you'll basically have an iron block LS2.

[nibs]

Originally Posted by Jon01

Is the intake a dual or single plane unit?
Auto or manual trans?

IDK that that cam will get you where you want to be powerwise. If the intake is a dual plane unit I'd be looking at it real hard too.
What I would do is sell the cam, carb & LS2 intake, stick the 243's on there and pick up a used FAST 90/92, MS3ish cam and run an OEM controller vs. the MSD stuff.
With the 243's you'll basically have an iron block LS2.

To be completely honest, Im not sure if the manifold is a single or dual plane. I am deployed overseas at the moment and the only way i can see it is in the pictures that I posted above. LOL I want to say its a dual due to the way the runners are at different levels on the two inner cyls and the two outer cyls. See what Im talking about?

The trans will be a 4spd auto(4L60E rebuilt)

The cam is actually making those kind of numbers if not more from other guys that I have seen with it, with no more than long tubes.

The fact of having the "iron LS2" is actually what I was going for, but Im not really wanting to spend more money on another cam and another intake mani(when I already have a 90mm opening). The reason Im wanting to go with the MSD setup is because of the ease and cleanliness of the whole thing. I dont have to piece together a factory ecu, a factory harness, then have that cut down, and modded, and then have all that tuned by someone. The self tuning technology is something that I have been eyeing for a while due to the simplicity of it all.

Im not trying to come off as Im rejecting your suggestions, but I just cant really go over budget anymore with the truck as I was going. Its one of those situations where I kinda have to choose between what I have!

[Jon01]

Are they getting that kind of power with an M6 or an A4?
My LS2 GTO made 452 with an MS3, FAST 90mm and 1-7/8" Kooks thru an M6.
An A4 would have been right around your goal of 425-430.

Facts:
LS2 intakes are not good performers.
Dual plane intakes are not good up top.
Cam is short on intake duration.

I have no experience with the MSD setup but anything that's "self tuning" raises my eyebrows as to it's ability to extract max hp out of your setup. I'd be curious as to the timing and fueling tables and how it reaches it's conclusions whereas the OEM stuff is tried, true and supports some BIG hp #'s.

Sorry but I just don't see you getting to your goal thru an auto with that combination of parts.

[68GMCCustom]

oem pcm/ecm have "self tuning" capability up to a limit. The parameters you select in the setup no doubt make a big difference its (an MSD atomic efi, FAST ez efi, etc.) ability to self tune. Get one wrong and wonder how well it does. Those systems also have a hp limitation which for many is fine. Keep in mind an oem system is also controlling spark...a FAST ez efi system for instance does not. Neither does the MSD w/o a ignition box like the 6LS.

that said...that looks like a single plane intake. I'd think with that cam you'd want a dual plane. When my setup was carb'd I ran GMPP's LSX/LS3 dual plane intake and was pretty happy with the low end performance. Never really dialed it in completely to give a top end eval. My cam is a 223/231@.050 .610/.617 112....and I've been thinking of bigger cams lately. .

[nibs]

Originally Posted by 68GMCCustom

oem pcm/ecm have "self tuning" capability up to a limit. The parameters you select in the setup no doubt make a big difference its (an MSD atomic efi, FAST ez efi, etc.) ability to self tune. Get one wrong and wonder how well it does. Those systems also have a hp limitation which for many is fine. Keep in mind an oem system is also controlling spark...a FAST ez efi system for instance does not. Neither does the MSD w/o a ignition box like the 6LS.

The MSD system does control the spark, which is very nice. The only thing that I would have to get is the trans control unit. I should clarify that the system designed for the LS system, does control spark...

[Jon01]

You really can't compare camshafts between cathedral port heads and rectangle ports.

You run what you want, I've shared my opinion. I think you're leaving HP on the table for small financial costs in the grand scheme.

[nibs]

Originally Posted by Jon01

You run what you want, I've shared my opinion. I think you're leaving HP on the table for small financial costs in the grand scheme.

Your opinion actually has been on my mind all day now that you have given it! I have been looking around on these manifolds to see what kind of cash I can get out of them and at the same time looking for a FAST mani too.