bubee27

Can someone please give me some info on the stock 96 lt1 heads?
Good or bad?
Porting and polishing??
Also give me the same info on the intake manifold??
Throttle body?? Better to change it out for a little bigger? 58mm??

Thanks in advance

Sorry for all the posts but i am just getting started on this project and i am trying to learn as much as possible before i make any set in stone plans. Better to do it once than have to put money into something that isnt worth it.

96capricemgr

iTrader: (1)

The 571 casting which you might have is generally frowned on forserious professional porting due to being thin. You will need to pull a valvecover and check. If you are saying "port an polish" though it sounds like maybe you or a friend decades out of touch is going to be doing the work and you could give it a shot since you probably wont be drastically reshaping. "port and polish" is 70s vocabulary, polishing is pretty much not done, maybe if someone wants to put the time into the exhaust side but these days most of us who want high end work just choose a good CNC porting shop and leave it at that.

Far as the intake there isn't a lot to be had in porting it but is a decent idea to have THE HEAD PORTER port it at the same time you have the heads done. I would expect your car to likely have the 138 casting intake which has smaller ports that more closely match the heads as cast than the earlier intakes which actually had larger ports than the heads. That doesn't matter atall for porting.

Far as the throttle body, lots of debate on that, if you are aiming for a modest goal though I would suggest a rebored stocker to 52-54mm and avoid the headaches that come with the aftermarket units unless you can buy a used aftermarket that someone already modded to work right.

DUDCOUPE

I know the edelbrock tb's are pretty much plug n play and dont need any modding

SwampWS6

iTrader: (7)

My $.02 is that with the throttle body their might be some hp gain. Their was a guy on You Tube who did a comparison on a 52mm and a 58mm. The end result was that he gained about 6rwhp from the larger TB. At the same time when he did the dyno comparison he did the 52mm first and by the time he put 58mm on, the car was hot as *****(which = less hp in some cases). But he also had a list of mods to go with it. So if your car is not heavily modded then your results could vary.

I was told by 96capricemanager when I joined the forum that 58mm will yield you nothing unless you have a list of other parts to make you need a larger TB(true)......

Rob94hawk

iTrader: (1)

These cylinder head casting #'s are best for porting: 10128374 and 10207643
Your heads have 561's, which are better stock than the older heads, so your best bet if you are budget restrained is to get a cam that will utilize those heads.

If you want more power then get your hands on the older heads that I posted above. Along with a bigger TB and a ported intake to match.

But like I said, it all depends on how much you want to spend cause it really does snowball.

Catmaigne

iTrader: (6)

Pull your valve cover and check the casting number. My car is a 96 and I have 643 heads. I think the build date on the door sticker was 10/95.

96z28_lt1

iTrader: (3)

my 96 also had 643 casting and was a 96. I also ran a 58mm tb on my head and cam car and had no issues with it, however a lot say they aren't needed untill your making a lot more horsepower.

96capricemgr

iTrader: (1)

You can slap it on without modding it but that doesn't make it right, hell they BBK/Edelbrock has actually gotten to need MORE work in recent years than it used to, the old one at least sealed the IAC curcuit, but the whistled and needecd the bleed drilled. The newer ones no longer issolate the IAC circuit don't whistle and still need the bleed drilled.

As a lot of us have said a lot of times, all the aftermarket TBs come with some sort of hassles.

Far as the 561s it has long been considered "common knowledge" that they were better but then some of the stock eliminator guys began trying to correct that myth, the stock eliminator guys can not do any porting and found those to be the slowest heads. GIZMO in particular has posted on this. Even said he believed he maybe just got a bad set and tried a couple more sets.

cardo0

bubee27 everyone here understands what u mean by Porting and Polishing so dont let a narrssist get to u and turn u away. This forum is really not policed at all and several clowns stalk here at will. But there is some valuable help to be found here. Other than that welcome to the forum.
If u want advice on your build u really need to post power goals and most of all your budget. For example getting to 400hp is as simple as a cam and vlv spring change. Going to 500hp will cost 5 times to 10 times that.

Lets hear what u got and what u want,
cardo

96capricemgr

iTrader: (1)

Understanding what someone meant does not mean the proper terminology should be disregarded.

GIZMO

iTrader: (8)

This is a myth. The 561's are the worst of the aluminum heads.

Rob94hawk

iTrader: (1)

Ah when then I stand corrected and let's hope the OP doesn't have them.

1994Z28Lt1

iTrader: (1)

For whatever its worth when I got my car back together I drove it for awhile with the stock 48mm TB. With my tuning software I was able to log the readings from the MAF, with the stock TB I would max out around 340-350 G/sec. I then installed a 58mm TB and ported the inlet of the intake manifold for the larger bores. With the same tune and same MAF mapping I would register 360-380 G/sec and even spiked 390 when I had it on the dyno.

Take it for what its worth but at my power level I did indeed flow more air with a 58mm TB

Unless you plan on having well ported heads and a cam to take advantage of them I would leave the stock TB alone

cardo0

No more bubee27? No reply in a week! So there goes another new enthusiast just asking for help. It is clear several enjoyed this topic and would like to help. And instead bubee27 receives degrading criticism from u know who. Yes that physiologically dysfunctional self claimed "very knowledgeable" LT1 blogger. U know which sorry azz im talking about.

What a big help,
cardo

Catmaigne

iTrader: (6)

Welcome to the internet.

cardo0

More like welcome to 96crazedmangler. Hes over on another thread now posting his dysfunctional statements: I am sure I have heard of a popular porter porting a set or two and then NOTHING on results which probably says a lot.

Got the OP worried asking: Everything OK at home?

No oversight on this forum here, so the saga continues,
cardo

NewOrleansLT1

Did you have to tune for the new TB or were you ok using the same tune?

96capricemgr

iTrader: (1)

I contacted the OP.

Here is his reply.

Quazz

iTrader: (1)

I really don't think you are qualified to speak about anybodies dysfunctions, nor are you even remotely qualified to speak about how to properly identify (or for that matter set up) a head.

NewOrleansLT1

One thing I can say about 96capricemgr (Dwayne) is he tell it like it is. Raw and Uncut. It's quite entertaining when your the audience but I can't speak for the host, and 90% of the time he's right.