dragonZ28

iTrader: (32)

I was in the same boat as you before my setup. In the end, there is no replacement for displacement. Any mod that can be done an engine can be done better on a bigger engine when properly set up for the application.

The 408 vs 402 debacle - Don't buy a 408 for extra cubes. Buy a 408 for block strength and piece of mind; no sleeving, know what I'm saying - sleeves can have issues. Also, if you want to spray, go 408. Iron > aluminum when it comes to handling the funny stuff

As far as power goes, it is determined by many things. All of these #'s you're seeing are #'s to the wheels; not at the crank. These numbers will vary greatly depending on drivetrain and mods. If you want the best power, get the best parts.

For my setup, I ran proven heads from TEA, one of the best head companies known. I wanted the engine to be able to breathe and exhaust. The heads can do both, but are limited by upstream and downstream mods. I have Kooks 1-7/8" headers; again a proven power maker. My intake is slightly restricitve still, but that is being remedied tomorrow night and I will only get this thing to churn out more brute power.

For the skeptics, power can be made. But, in your favor, lackluster power can be made as well. If you are going to do this setup, buy a shortblock from a reputable builder. Buy your heads from a non-budget cylinder head company. Budget means inferior - period. You want superior, non-budget heads for a multi-thousand dollar setup, so don't skimp. Look for area under the curve, not peak flow numbers

It's all in the parts combination. Good headers are useless with crappy heads and/or intake. Good heads are useless with a crappy set of headers and/or intake. A good intake is useless with a crappy set of heads and/or headers. Make it breathe, make it exhaust, make it a beast. Get the best of the best, and your results will be the best

Don't fear low numbers - fear a low budget

camarokid94

iTrader: (2)

man i need to get them money to do my 408 i cant wait after all the posts GGRRRR

408LS1TA

I've got a 408 built by Texas Speed... AFR 205 heads... 244/248 .612/.615 115lsa cam.. 1 3/4 pacesetter LTs, ASP underdrive pulley, LS6 intake, 3" ORY, Hooker catback... along with the Racetronix PnP kit & 42# injectors.. and a SLP maf... stock TB. It's an Auto with 3.23 rear gears & 3800 stall converter. It was trailered to & tuned by Speed Inc in Schaumburg IL when we were finished putting it together. It put down 450hp/425tq with zero miles on the motor.... running a 'low' 10.2:1 compression ratio... on 93 octane.

I'm hoping with a FAST 90 / NW 90 setup... it should pick up a couple more ponies. It falls off some at the top... think it's running out of breath.

camarokid94

iTrader: (2)

Humm....
well im gonna go with the TSP 408 with about 12.5:1 and there texas giant, my AFR 205s that are being ported and an asp pulley, 1 3/4 LTs and ory to a magnaflow cat back, 42 lbsers, gonna keep the LS6 intake for now and hope for 500hp and 480TQ.
I hoper ill get there i know there more with a 90-90 swap but thats another G i dont have.
im gonna drop a post somewhere else and see what everyone things of my plans.

WS6FirebirdTA00

iTrader: (33)

i may be going for a 470-480 hp 347 now, i was pretty happy with what my setup did on stock compression, shitty quench and ls6 intake

Brandon Boomhauer

iTrader: (10)

408
244/248 cam
stock untouched 241 heads
10.96:1 comp
300 on the clock
ls6 intake, pacesetter exhaust

468/460!

DocEwww

iTrader: (1)

ty_ty13

iTrader: (42)

hope you like race gas for your 12.5 CR.... and why the AFR 205's? your spending alot of money for a head that doesnt flow well up top...
i'd shoot for the stage III or II Darts.

Patrick G

iTrader: (14)

Common misconception about AFR 205s is that they don't flow well up high. That's simply not true. They put better rwhp and 1/4 times than most skillfully ported LS6 and 6.0L heads on the market. Remember, flow numbers only tell half the story. The 205s are good for well over 500+ rwhp on a 408. Just need the right selection of supporting mods.

2001 Pewter WS6

iTrader: (43)

Mine runs on Sunoco 94

ty_ty13

iTrader: (42)

you must have the timing turned down

383ss

iTrader: (14)

Here's mine. can't believe I hadn't posted it already :lol

iron 408
M6, 4.10 gears, dyno with 28" slicks
12.8:1 comression
CHS ported 5.7L heads flowed 293@600
FMS 246/250 .632
1 7/8 QTP headers
all the bolt-ons
Fast 90/90
stock Rockers
Melling lifters

550rwhp 515rwtq

It dyno'd 545rwhp and 535rwtq with 1 3/4 headers


I just swapped over to a Vic JR intake and will dyno it saturday. hoping for ~570rwhp. will be at the track sunday, hoping for 10.0's @ 135. I never quite had everything worked out with the old setup, but I'm sure it would have gone 10.3's.

WS6FirebirdTA00

iTrader: (33)

wow so the larger headers lost a good bit of torque...

383ss

iTrader: (14)

yep, it did. you can see it helped quite a bit up top though. it only gained 5rwhp peak, but brought my peak out another 500rpm and added up to 35rwhp

[IMG]http://mofbody.com/john/1%207-8%20vs%201%203-4.jpg[/IMG]

gollum

iTrader: (1)

Check out this stock 241 head, ls6 intake, and 408ci. https://ls1tech.com/forums/dynamometer-results-comparisons/462218-stock-headed-408-468-460-w-ls6-pacesetters.html
I bet some 205 heads will really wake it up.

Z'mnypit

iTrader: (58)

Im about to raise mine to around 12.1:1 Maybe 12.5:1 If I knew then what I know now I would have done that from the start. Screw this 10.7:1 even though it really shined on the bottle. Over 100hp pick up on a 75 shot.

ty_ty13

iTrader: (42)

what springs, lifters, and rockers you running?

that vic will really let those headers breath!

383ss

iTrader: (14)

Manley springs, Melling stock replacement lifters and stock rockers.

383ss

iTrader: (14)

my 12.8:1 picked up 130rwhp on a 100TNT shot. I thought that was fing insane.

Z'mnypit

iTrader: (58)

Damn, The TNT kits are defiantly bad ***. Thats crazy spraying on 12.8:1 you sir have some kahunas. I thought Id be pushing it spraying on anyhting over 12 but it seems like the more I read if everything is good then your safe. So I figured Id raise the compression on up to gain more power on the motor, beings I dont spray that often.