97badass

iTrader: (8)

Ok the first question is how much better than stock lt1 heads do the lt4's flow? how much better is the intake flowing capabilities? and then my last question is what kind of hp should i get out of switching to the lt4 heads and intake with a 52 mm tb, cai, and the gm847 cam? and is there anything i should add to that besides a good tune?

also i will be adding lt's with a ory with a catback. and do you gain any kind of hp by deleting the smog stuff, besides losing fuel mileage? i get over 30 with it stock soo i think i can sacrafice some fuel mileage

slick1851

Are you looking for exact flow numbers on the heads? I would just get your stockers ported if your staying with stock cubes etc...Our heads can get a good amount of power out of them


You cannot buy the LT4 setup from GM anymore, you will have to find people selling them

97badass

iTrader: (8)

i was just wondering if they actually flowed enough better to justify buying them. Do they increase compression or anything? or just flow better? but my main concern was the hp gain.

96capricemgr

iTrader: (1)

IGNORANCE is driving you at this point. STOP you are not ready to buy anything.

I know it is not nice and is not what you wanted to hear but it needed to be said.

The LT4 stuff was the ticket a decade ago, today, especially on a 350 it is an outright mistake.

You are also considering too small a TB and too big a cam.

Best advise anyone can give you is go back to square one with your research, popularity does not mean worthwhile, a LOT of guys are no man enough to admit mistake and insist whatever mediocre setup they have is awesome.

Look at sigs for dragstrip times and MPH and try and get a feel for how the car is setup and the location they are in, that will tell a very different story than what everyone says is great.

Yesterday I drive 360 miles, 150 each way to/from track other 60miles is to/from home/work, clipped off 12.3-5 at 108mph all night full weight, closed exhaust etc.. Feels go to be asked where the bottle is when there is NOT nitrous on that car. Keep in mind my car is a big heavy Caprice.


You need a stall if an A4 and gears reguardless of tranny before you can consider heads and cam, trust me my first cam I did with stock stall and gears and I am man enough to say I made a mistake. We all do, those of us who admit and learn from them go faster for less than those who refuse to admit it.

92_RSCamaro

It all in what your goal is for the car and how much your willing to spend. For the money LT4 heads are not worth it to me. You could look into getting your head ported, I would recommend llyod elliot. Here are some specs on a LT4 vs a LT1 in a Corvette.

97badass

iTrader: (8)

all in all i would like to gain about 100 hp, or at least hit the 350-400 mark...and i dont really have a lot of money to spend on the motor, and i would like to stay as far away as possible from the juice. to me juice=cheating imo

joelster

LT4 heads get a very bad reputation simply because of their price. The "kit" that used to be sold with the heads/intake, and cam was like $2500.00 or something like that. The heads flowed around 250ish on the intake, about the same as a decently ported set of LT1 heads, but below the A.I. or LE2's. IF and I mean IF you can get your hands on a set of used LT4's for dirt cheap, then by all means go ahead, BUT if you need to spend more than $1200 or so to get them along with the intake, don't bother. You'll be far ahead sending your LT1 stuff out for some porting from LE or AI. FWIW the '96 Grand Sport 'Vette's with the LT4 motors usually ran around 13.3 in the 1/4 which is about .7 faster than the LT1 "Vettes, and this was with a much milder camshaft than the "hotcam" that comes with the kit. I remember reading on another forum I think it's grandsportregistry.com or something like that with a nuber of guys dynoing their cars bone stock, and a bunch were well over 300 at the wheels.

always faster

iTrader: (6)

You are totally right.He should only spend money on lt4 heads if he can get them cheap.At around 1200/1400$ a pair he should send his lt1 head to Loyd and have them ported ans install a cam for the same price

BUT!!!!

You are again totally right on the lt4 long block in the vette.The where doing around and over 300whp on a 330fhp wich is really telling me that these engine where underated.

I was one of the lucky one to pick up one of these engine when they sold there last one.I purchase one for 3k brand new in the crate and its now a full bolt on and i would not be suprised to bump 330whp when i get it on the dyno with a perfect tune

96capricemgr

iTrader: (1)

You need to look for RESULTS from guys recommending parts. From what I see most of the guys recommending LT4 AFR etc. lack results, they are making recommendations based on bench racing theory.

Don't listen to me though, listen to the original LT1 tuner and a guy who has been involved in real racing longer than most of us have been alive.
https://ls1tech.com/forums/showpost....12&postcount=6

Then again maybe the goobers with no times in their sigs know more than Ed?????

I will say that I still question his statements that on a stroker LT4s are the better starting point BUT that could just be be cause I have yet to see results from a stroker with LT4s ported by the right shop. I do believe there comes a time when strokers are moving enough air to benifit from more port volume BUT I am not seeing that in results yet.

GIZMO

iTrader: (8)

I had great results with the LT4 stuff. Comparing the LT1 heads to LT4 heads is like comparing LS1 heads to LS6 heads. The LT4 head with the optimum cam/tune will out perform the LT1 head with the optimum cam/tune. If you port both the results will be the same. If $1,200.00 is too much for castings you probably can't aford what it takes to optimize the combination. I spend more than that to blueprint LT1 heads (no porting).

Daren