Abdullah

iTrader: (2)

which heads will give me the best power NA from low end to top end RPM?

i will soon buy a 1996 caprice impala SS and wanted to do a 396ci LT1 i want a good set of cylinder heads that are able to to stay in bar with the LS1 heads, so i thought a converted GM 18* heads would do that since they will accept stock headers and even may still accept stock style 23* pistons and will make very good power.

i know that MindGame did a converted and modified GM 15* heads with modified LT4 intake manifold in a solid roller 383ci LT1 as i can remember in his LT1 camaro, it did 540 rwhp and did 9's@~140 mph as i can remember.

the GM 15* heads by the way are actualy made of the GM 18* heads that the GM 18* heads had its valve guide roller 1 degree and angle mill these heads 2 degrees to get the GM 15* heads.


so what would you say do i go with a converted GM 18* heads and modified LT4 intake manifold or AI's TFS 215cc LT1 heads with AI's street/strip LT1 intake manifold?

Formula350

iTrader: (3)

o_0 What the hell are you planning on making? 750hp? Because, I don't think your average H/C motor is going to merit the need of either of those heads. A nice LE3 H/C/I combo will put down around 450 I'd think.

Here's a better idea, take the money it'd cost you to convert heads, and just run a supercharger. One guy was running a fully stock LT1 (cai, except headers and catback) and put down 423rwhp. With ported heads, a nice blower cam, and all the other mods you'll make plenty of HP to walk LS1s. But keep in mind, you're going to be in a heavier car than F/Y bodies.

Tireburnin

iTrader: (42)

The Ai TFS heads. Don't try to reinvent the wheel.

FASTFATBOY

iTrader: (23)

If I remember you have to have headers fabbed for those heads, along with:
specific rocker arms(shaft)
specific pistons.

The engine mindgame built had an old school set of gm heads on it and made BIG power through a stick on pumpgas.


A Le "package" aint gonna put down 450rw through an auto.

The REAL power to be made is in headflow, PERIOD. A set of 18* heads will make more AVERAGE power than a set of 23* heads any day all day.


I wish I would have popped for a set now looking back. I would say I could make another 100 hp at the flywheel with a set of GM 18* heads on my 383. That would put me close to 700 on pumpgas.......with that said....

Build 408 LS1 make the same power with a hydraulic roller and lower compression with proven setups.

A buddy makes 525rwhp through a 4L80e and a 12 bolt with a 408 LS1 on pumpgas and a hydralic roller cam and AFR heads. Runs 10.50's on motor weighing 3900 lbs.

IH8FORD

iTrader: (6)

i am with him I wanted to build a big power lt1 for my 97 and decided to build my 99SS the power of the LSX platform is to easy to pass up.

Abdullah

iTrader: (2)

yes, i plan on a big power NA, like 520+ rwhp i want to do that with a 396ci LT1. also the sound of Hooker LT's combined with Borla in my sold 94 A4 LT1 camaro was awsome and more beatiful than my 2000 LS1 camaro. not sure if the 1996 impala SS will have the same sound as my 94 A4 LT1 camaro.

Abdullah

iTrader: (2)

i was told that the stock LT1 headers will fit the GM 18* heads but i'm not sure on the pistons.

Formula350

iTrader: (3)

The fact he got a B-Body totally slipped my mind at that point heh Good call.

ulakovic22

iTrader: (12)

If you have any kind of budget then go with 23* stuff and a power adder of some sort to make that power. If not then go 18*. It's all a matter of money really. Build the best motor you can for the money you want/able to spend.

96capricemgr

iTrader: (1)

The AI 200cc stock casting heads are capable of over 500rwhp on pump gas, and the 215cc Trickflows are better. They will get you over 500rwhp through an auto IF you follow instructions well.

Talk to Ron and Phil, tell them your MPH/ET goals and they can help.

ulakovic22

iTrader: (12)

Are you talking about solid roller and spinning it to 7000? I'm not sure what the OP's plans are but most people don't want that from a driver, a race car sure. Of course then you get into the debate on what streetable is, lol.

Abdullah

iTrader: (2)

i want the car to be street/strip. actually i don't want it to be solid roller i want it hyraulic roller because it is more streetable than solid roller. and yes, i want to spin the motor to like 7000 rpm.

MEAN LT1

iTrader: (2)

I disagree, I think port velocity is more important than head flow. I think too many peopel get caught up with head flow.

FASTFATBOY

iTrader: (23)

Oh really? Why do you think Nextel guys use a canted valve low angle head? If a 23* head was the end all to be all nothing else would have been developed.

There are 10 and 11 degree heads out there now.

Lower angle heads will ALWAYS make more average power than a higher angle head, thats really a no brainer. Look at an LS1, 346 inches and makes 75 hp more than a 23* headed LT1. Stock LS1 heads flow stock what a midline ported LT1 heads flows.

Port velocity and head flow almost always go hand in hand. Most old school rules are WAY out the window with the advent of EFI.

ANYTIME you roll the head over and make the shot in the hole straighter the air flows easier and makes more power.

Abdullah

iTrader: (2)

personaly i prefer smaller optimized port with higher port velocity with smaller corsssectional area with adequate flow numbers over higher flow numbers and less port velocity and less optimized port, specially for the intake ports.

FASTFATBOY

iTrader: (23)

Really is amazing how what is read on the web is preached as gospel.

I guess you guys thing a 250 cc port is too big for a 6800 rpm 383 to dont ya?

strokedz

iTrader: (1)

I am running the Ai tfs 215 on a 383. The track I run on is not that good and the corrected DA is in close to 1500ft. most of the time and I still have ran 10.6x with a high 1.4 60' and have ran 128.7 mph. I think that for the money the TFS head would do what you want with no trouble.

flyinZ

iTrader: (15)

From what I've seen, and what Ron has told me..The TFS head, would be your best bet.

^^^Dude, tell me more about your setup? Have any pics/vids of it? PM me if you must

Abdullah

iTrader: (2)

you are running very good 1/4 mile times and mph for a 23 degree heads. but you are using a different intake manifold than the stock LT1 intake manifold but still you have very good times and very strong car.

Abdullah

iTrader: (2)

i too beleive the AI's 215cc TFS LT1 heads would do me 10's@~128mph maybe a little more but i want something unique on my car. i will buy it today it is a black 1996 LT1 caprice impala SS.

i will keep the GM 18* intake/exhaust ports size to the minimum and focus on optimized port shape for higher port velocity with adequate flow numbers with matched custom hydraulic cam. i will use an edelbrock LT4 intake manifold since the GM LT4 intake manifold is discontinued. the edelbrock LT4 intake manifold will be ported and modified to work with the converted GM 18* heads. the engine will be a 396ci LT1 with a 11:1 compression.

also i was told the stock headers will work with the GM 18* heads.

i don't have any pics/vids yet since i didn't buy the GM 18* heads/edelbrock LT4 intake manifold yet but i will in the future.