Patron

Oh you said Richards compression in the article I figure around 11:0 to 11:8. That's what a normal 427 engine would make using any other aftetmarket heads. They will all be in the same ball park + or -.

Tuskyz28

Now we need to reach out to Richard and have him test some headers on that same engine. 1 7/8 vs 2 inch and see what happens.

Patron

One would probably peak a little more it's all about the set-up. A 1 7/8 stepped into 2in. header would be better to me. I try to think in terms of velocity on both the intake and exhaust and most of what I've seen, most have Stepped headers (some times 3 times stepped) in matching the exhaust port size and then stepping it out more for a higher RPM=HP. No need for soggy air, in a over sized header. Air is going in and out with velocity if you have more lift with a better exhaust port then the exhaust may need to go up in size. What goes in must come out. Each engine combo may require something different in header size.

big hammer

Military sucks.

Regardless, there's no cathedral ports running near mid 7's NA.

I've said there's no "best" intake, more like what are your goals...?

Same as what's been said about heads here.

East Side Ivan

I have a 2000 rs and it's my baby but I'm feaning for more speed I had it for 4 years but the last year it's been sitting cause I been saving to get it to its full potential but I want a ls3 can I do it yes or no and oh yea it's a T-top

Tuskyz28

Who's the fastest all motor to date? I would guess Sam racing.....

Patron

Something old to read about cathedral and rectangular ports. *Dragzilla knows his stuff. He also has a new class limited build that's Rather nice.

http://www.yellowbullet.com/forum/sh...=495454&page=3

SoFla01SSLookinstok

Good read. I stopped at Brian Tooley. Laid it down cut & dry.

If I was ever going to use a square port head. I would want an ls7 head. Just me.

blk00ss

iTrader: (66)

What I've been screaming all along.

NAVYBLUE210

Read The whole thread, last post nearly 4 1/2 years old,
Most over 5. My point is time, knowledge, & products
continues to evolve. Both Brian Tooley & Martin Smallwood
Agreed that to take advantage of Rectangle Heads both
LS 3 & 7 the following are required size ~400+ CI, Bore
~4.060"+, 7000+RPM and Shorter Runners (carb style or
Expensive sheet metal at that time).

The advent Finally of mid, and short runners for the FAST
LS3 Intake, along with LLSR Cams is a game changer.
With Aftermarket LS 3 Heads Like MMS, MAST, AFR,
TFS, and others with flow rivaling some LS7 Heads
These provide viable alternatives to LS7 Combos
With FAST or MSD Intakes.

Patron

I did say it was a old post. Here's a better updated one.

http://www.yellowbullet.com/forum/sh....php?t=1568978


Navy I hate to tell you this but a Ls3 is Not better than a Ls7 head and is not even a Rival also it's not a alternative it's for someone who just wants Ls3 heads or Doesn't want to change there top end (you can change the valve angle to what ever you want 12 degrees the runner's are in the same Place). Anyone buying a head that's over 2k is aftermaket so why buy a LS3 heads when you have the Top of the Food chain in Ls7's. I don't know about the 4.060 part we can go below that to 4.005 but the 7k + for rpm ....Is spot on. It's all about the final product of what someone is asking and whats there budget. I get what your saying about Development has come along way.

Navy on your same engine I'd say a TFS Ls7 head would be worth 20 hp just on principle alone(Carb style intake being used).Throw in some bowl and short side work. 400 easy with hella velocity. One day I may get me a pair of TFS Ls7 heads & start with a better casting. What I've got now will work for the time being. I got another set to get done in me.

jleews6

iTrader: (2)

As far as EFI goes does anyone else think that a big limiting factor for the ls3 head is the intake? I see allot of stock SB LS7s go well over 600 WHP and have good power under the curve but I cant remember the last time I saw an ls3 style setup go over 600 on any CI. They seem to go flat around 550 or so. I wish there was a way to put a "Mamo ported" LS7 MSD intake on a ls3 motor to see what happens.

Tuskyz28

The limiting factor is the intake on guys running LS3/LS7 heads. All those big heads need single plane intakes and rev past 7200 rpm to get the MOST out the heads but guys dont run them because they dont want to cut the cowl (F body 4th gen) ... so it kills the OVERALL PERFORMANCE of the car at the track. Im still impressed by the Tims 454ci mustang that used stock LS3 heads and went low 9s on motor but the car had a single plane intake and we all know Fox body cars are way lighter than camaros/trans ams....

big hammer

Now with different length runners for the fast that opened up the RPM options for fbody guys without cutting up the cowl

big hammer

Nope.

SoFla01SSLookinstok

The stock LS3 heads are the best in the world. "Cheap heads" but better than anything else ever!!! Anyone that thinks otherwise is a hater & doesn't know what they're talking about. (all sarcasm)(except quote).

PS: Maybe that will help hammers vagina itch.

Seriously, after just seeing a thread 5 yrs old, this is not a new topic. That has been stated before in here. If you like LS3 heads good for you. Make em work well & eat. Just because some people may not like them, for many reasons, try not to be a bitch & cry, whine, like a child. But but but why? waah waaahhh

Hammer, I think your engine is cool. Really like to see what it puts down & runs.

What was the main reason you destroked the ls7?

Tuskyz28

Oh yea.... looks like what i said years ago is still being said/proven today. The LS7 head outshines a LS3 head big time. Most guys forget the LS7 head comes already cncd from GM.

Rise of the Phoenix

iTrader: (27)

This thread goes great with a 12 pack of Natty Light.

speedtigger

iTrader: (16)

I am afraid I would need something a little stronger.

big hammer

Your strawman sarcasm is strawman sarcasm

I just said stock ls3 heads are better than stock cathedrals


I only built the engine this way because that's what I wanted to build. No other reason. And so far I'm really happy with it. Shitty ls3 heads and Shitty plastic intake and all lol