I didnt see one of the topic starters questions directly answered here, so...
The LT4 intake is a necessity for LT4 heads, thats it. The intake PROBABLY will not net you much for gains on a stock LT1 without the matching heads. But that doesnt make it a bad plan, you did ask if you should also get the heads, so to me thats not a plan its a simple freakin question.

The LT4 intake can be port matched to the Lt1 heads in most cases(depending on the casting quality), but dont expect a big gain if any at all. Where you'll see the gain is with the LT4 heads, gasket matched to the LT4 intake. If you port match to the LT1 head, your intake would then be useless on LT4 heads. So get the intake, save for the heads, do the install, get it tuned and enjoy!

GM wouldnt have designed the head/intake setup if it didnt work good on a 350 inch motor. After all, thats what they installed it on!

If I may add, a more budget minded approach would be to have your stock heads and intake ported with bigger valves. When you save enough money get a better cam than the LT4 hotcam and you'll really see an improvement.

Call Harold at www.portpros.com, he can set you up with a nice package that performs for a nice price. When they show up, send him your cores and you'll get that charge back.

 

Just port your LT1 heads and LT1 intake...

 

Yea, keep it simple and use the money elsewhere..

 

Says the guy with the 1000lbs lighter and half a second SLOWER car.

I am the one with useful knowledge you know just enough to be dangerous. If you would STFU and read you might be able to actually make your car quick.

It is sad that most of you would rather blindly help someone waste money rather than help them get the best bang for the buck. It is also sad that even after I DETAIL why ist is a mistake someone has to come in and say that there might be some gain. I DETAILED WHY THERE WOULD NOT BE and if half of you had half a clue this myth that the LT4 intake is higher flow would die because I am not the only one who has posted intelligent info on this. Heck this forum is one of the places where I have learned a far amount from a SELECT FEW like some of the guys discussing basically this topic right here . I would consider GIZMO, Ed Wright and Ellis all more knowledgable than I and they all say more or less what I am here. So why don't those of you disagreeing with me here pull your heads out of that dark orafice they are stuck in and use the search to LEARN rather than continously spreading your ignorance.
Here Ed specifically quotes me and agrees about LT4 heads on a 350/355. What do I know though?

I can backup my assertions I challenge the rest of you to do the same rather than attempt personal attacks to discredit me, yes I have launched attacks at ignorant fools like merv here but as I said I back it up which is where I discredit him not with the attack but with facts.

 

Off-Topic,

How can you comment/criticize a setup you don't even run? The entire purpose of the LT4 series is to get the most out of the 350 which is why chevrolet designed it in the first place. The LT4 components are designed to out flow, out manuever, and out handle the LT1 series in all aspects. Either your going to make power with a really good cam, or a really good set of heads, and if your lucky enough you'll get it right so your get the most out of both. Displacement doesn't mean a thing. It's about having the right combination and matched parts. The first thing any credible cam designer will ask you is what kind of heads will you be using, and they'll design the appropriate cam to match that specific set of heads. It doesn't make any sense to go around bashing other peoples setups because you "think" you got it all down. You'll always find someone with a counter statement to your "opinion".

 

I was smart enough to do my research before buying and avoid your mistake.
When someone like Ed makes a statement as he has on the LT4 on 350 threads a smart man will listen, he has been racing longer than much of this forum has been alive and is unquestionably a top LT1/LS1 tuner. I am not saying he is 100% right 100% of the time but you can be sure everything he says has some good solid roots in truth. My beliefs are not founded solely on his statements on the subject, though they are a solid credible well recognized reference I can make.

Big heads on small cubes need RPMs the stock computer is pretty restrictive there, if I were looking to build a aftermarket injection controlled 355 spinning to 8500rpms then I might look at LT4s. I am not saying they are useless just the vast majority of the time missused.

 

and "The Merv" out of ******* nowhere!!
Jeesh bro, relax.
___

LT4 parts are overrated, and not worth the time IMO. If you could get a complete LT4 conversion kit, including the cam, intake, retainers, springs etc for a killer deal... why not.

But I say give L. Elliot a call.

What? an LT4 is an LT1.

Its got a better cam, better intake and other things to make another 50 hp.
Its not even close to getting the most out of a 350 CI engine.

Not to criticize you, but you need to be more educated on your responses.
______

96caprice is right. LT4 parts are overrated.

 

96capricemgr your absolutely right. I made a mistake of putting together an engine that has matching components that bring it to it's full potential. I'm sorry, and I applogize to you an Ed wright for this. Next time I work on my car I will Mr. Ed Wright first to get his permission because even though the LT4 was introduced in 96, he has been around it much longer than 1996. Surely he is a smart man that knows his stuff and runs 10's, but the man that helped designed my setup knows his stuff and runs 8's ... now just what point are you trying to make? and why are you giving reviews for parts that you don't even own?


BTW can someone show me a 210cc LT1 head? I really want to buy one. Surely I can find an LT1 head that outflows them and all.

 

The lt4 stetup(intake,heads) is pretty useless because its too expensive for what it give you(my taste).

Dont get me wrong here i trully respect everyone that modify there car.So if someone want to make the lt4 conversion thats cool and he probably be happy with it.

But just to let you know that a stock heads and intake properly match,ported can take you in the 9sec with a practicly full weight f-body

Here is a good link of what a good setup can do.You have all the info and also a couple of vids.

http://www.advancedinduction.com/Abare.html

Enjoy

 

I agree very well put, but those are highly ported Lt1 heads on a large displacement motor, with a monster cam that revs to 7K+

I've been on these sites for years, and this is the first time I have every read about anyone bashing the LT4 series. The only time when someone pertains to using LT1 components over LT4 components, and when they are on a budget trying to save money. I'm still trying to figure out how a head that is flows more, and pulls higher numbers is supposed to lesser than a head that gives less results. The only people that have had poor numbers from using LT4 heads, are people that used the wrong combination of components.

unless somone presents statistical data showing comparisons of different cams matched with LT1 heads and LT4 heads, I'm affraid "opnions" are void.

 

LT 4 heads worked out fine for me 8.92 @ 154.28 3450 raceweight

 

I am cool, but that guy just comes out and criticizes everyone for their stuff cause it's not the "best", and his attitude seems like he is the best. Everyone is going to want what they want, don't dog on that. I have stuff in my car that isn't the "best", but I bought it and it works.
Hey Caprice, if you want me and everyone else to have the "best" **** in your opinion, then get your *** over here and buy it for me. I earn my money giving you the right to be a terd, so shut up.

 

This is why they probably are cool, and you a Douche. They probably say "hey, look at this.." instead of how we have our heads up our *** cause we are looking at LT4 stuff.
Get a life, and a girl, cause you need one if you have the time to sit there and type a book.

And also, I am happy with my Car the way it is, it's doing pretty good. Never said I had to be to your standards..

 

Hey.. there's another guy out there stating the same..
Hmmm, makes you think.

 

And to you all that are reading this and laughing/whatever you are doing, my apologies for disturbing your day.

 

Other than the LT4 heads show me another LT-X series that outflows the LT1 that's made for the LT1?...... my point exactly.

I'm not talking about Stock LT4 parts. No body is. No ones compairing an LT4 engine vs. and Lt1 engine. Were compairing the heads/intake and thier potential.

"Not to criticize you, but you need to be more educated on your responses."
and you really should learn to take your own advice.

again why are people who don't own these parts reviewing them?

if you guys want to debate. Show me an Lt1 head that flows the equivelent of an LT4 head.

 

Do you guys realize the guy who made this post hasnt posted again? Think he was scared away. Why do we make such a big deal about the LT4 thing? Everyone knows how 96capricemgr is, weve come to expect this from him. He makes great points as usuall but comes across as a butthole. That's just who he is. I guess now I see you just have to weed out his attitude and absourb the good info out of it.
I have a LT4 intake. Lloyd suggested it after he did my AFR (OH NOSSSSS) heads for me. I think it was under or around $300 for it ported. No big deal. Never expected anything extra from it just went off his recomendation. Doesnt mean it's going anywhere anytime soon.

 

These types of arguements helps give the LT4 heads/intake a bad name.
Helped me pick up a new set dirt cheap. Sent them to Lloyd , they worked
out very well on my 383.
Nice inexpensive set up.

 

Thats your only point... that the LT4 head outflows the LT1 head... so?
That doesn't make it the best choice.



These are the reason's the LT4 is better. Not just the head.

New camshaft design
Larger valves
Roller rocker arms
Revised Head design
Head Gaskets
Revised Piston Design
Positive-twist top piston rings
Fuel System
Intake Manifold
Roller timing chain
Specially machined crankshaft
Dual-mass front torsional damper
Nodular iron main bearing caps
Teflon rear crank seal

The big difference is not the intake, but the heads.

"The big difference in the heads is the intake and exhaust ports. Both are larger with bigger radius bends. The "short side" radius of the LT4's exhaust port in particular has been increased to reduce back pressure at higher RPM,s. A throat cut just past the exhaust valve seat also opens up the exhaust port. (Unshrouding valve). The Intake port volume has increasd by 25cc. Increased from 170cc on the LT1 to 195cc for the LT4. The flow through the heads have been increased from 212CFM (Cubic feet per minute) @ 28" (711mm) (LT1) to 240CFM (LT4)."

Educated enough?

 

This post is not to prove anyone wrong.. some might alrady know this stuff some might not. This is based on a true LT4 motor not the LT4 kit


To discover the differences between the LT1 and LT4 powerplants, we decided to take a stock 1994 LT1 Coupe and put it up against a stock 1996 LT4 Coupe, and see just how much of a variance a few minor internal engine modifications could make. This track test will also put to rest that endless rumor: "... It's just a set of heads and an intake manifold bolted onto an LT1 bottom end." In a sense, that's true. However, there are many more subtle differences in the bottom-end assembly that people seem to overlook. On the surface, it doesn't really make sense to manufacture an engine, such as the LT4, for only one year of production. But with the four-valve LT5 already killed, and the new LS1 reserved for the C5, the engineers were told to redesign the existing small-block to produce at least 10 percent more power than the LT1 to satisfy the immediate need for extra power.

First, let's start with the obvious-the cylinder heads. As you may already know, the LT4 heads aren't reworked LT1 heads. They are a completely different casting.
GM Powertrain engineers decided to take the easiest and most effective route toward more power by increasing the volume of the air/fuel movement through it, so they built an all-new cylinder head.
In comparison to the LT1 head, the new LT4 head has had its intake roof raised by 0.100-inch and the radius, from the port to the valve bowl, has been smoothed out for better flow. To improve the flow of hot exhaust gases, the exhaust ports have been made wider, while the rear walls have been reshaped to allow quicker travel of the gases from the seats to exhaust flange. In addition to the modifications of the ports, the combustion chamber has been redesigned to improve flow to and from the ports, and larger 2.00/1.55 intake/exhaust valves have been fitted.
The LT4 intake valves are not only larger, but due to their hollow stem design, they're also lighter. The intake valves weigh 85 grams each (25 fewer than the LT1 valves), while the exhaust valves, which are partially filled with sodium and potassium to promote better heat dissipation, weigh 75 grams apiece (20 fewer than the LT1's).
One of the most obvious features of the LT4 over the LT1 is the higher 6300 rpm redline. Since the redline was increased 500 rpm, the engineers had to improve the valve springs significantly. They did this by using an egg-shaped, single-coil spring with 100 lbs. of seat pressure, as opposed to the LT1's 85-lb. pressure. The closed seat pressure is 260 lbs.
The 1.6:1 roller fulcrum, roller-tipped rocker arms are a modified version of Crane's design. By using these extruded aluminum rocker arms, the engine effectively increases the lift with the added advantage of less engine friction and a smoother idle than the LT1. The rocker arms sit on special shouldered 10mm studs, and are tightened down until they bottom out. This design eliminates the need for any kind of adjustment.
To further maximize the performance potential of the lightweight valves and roller rocker arms, a larger camshaft was selected. The LT4 cam lift profile is .476 intake/.480 exhaust, while the duration is 203 degrees intake/210 degrees exhaust at 0.050-inch lift. It also has 115-degree lobe centers and is installed one degree retarded, which raises the engine's redline by 150 rpm.
Since the LT4 heads have been reshaped, a new intake manifold had to be designed; the LT1 intake will not fit. The new intake's runners are matched to the bigger ports in the heads and large 3.5-gram injectors replace the LT1's 3.0-gram injectors. In addition, the external EGR hardware has been eliminated.
There are also several lower end modifications for increased strength. The notches in the LT4's piston to clear the valves are 3cc smaller than the LT1, resulting in a compression ratio increase to 10.8:1, from the LT1's 10.5. The top compression rings in the LT4 are slightly chamfered, causing them to dish when compressed in the cylinders. This new design produces a better seal under positive compression loads to handle the engine's higher cylinder pressure. Other bottom-end modifications include undercut and rolled journals in the crankshaft, steel crankshaft drive with an 8mm chain and a dual mass torsional damper.
With the subtle differences between the LT4 and LT1 in mind, we selected a bone-stock model of each to see just how wide the gap in ET slips would be. Gerard DeSantis, who own the black '96 LT4, met up with David Tortolani's red '94 LT1 at Raceway Park in Englishtown, N.J., so we could determine if those engine modifications really make a difference in the quarter mile.