30th t/a

iTrader: (51)

I currently have a LQ9 6.0 and I'm trying to decide to either turn the 6.0 into a max effort H/C setup with CNC TFS 225s, 11.5:1cr, ported FAST 102mm, ARH 1-7/8LTs, and a wicked cam. Or turn the 6.0 into a 408, and run stock 243s, 11.5:1cr, LS6 intake, pacesetter LTs, stock ported TB and a custom cam.

Its one or the other for now. Thats what my budget allows.

Ive done months of research and the H/C 6.0 setup should get me 500/450 and the budget 408 setup should get me 450/470 with massive low end & mid range power. I even overlayed dyno graphs between 2 similar setups. The Budget 408 beats the H/C 6.0 up to 5000 rpm, then the H/C setup takes over.

My car is a street car. I may go to the track once or twice a year for fun. I'm pretty sure the H/C 6.0 would win the drag race over the budget 408.

I know if I did the 408 now, I could always upgrade the top end and make 530/490 later on. But I also think a budget 408 with its massive low end power with my 3.90 gears might be worthless when trying to hook up on the street and it might be better to have a little less power down low (for traction) and build for more top end power which would favor the H/C 6.0.



let me hear your thoughts on this

Philip Pugeau

I just recently had this experience. Had a heavily restricted 383 making 330 rwhp/342 rwtq. Just had a cam+exhaust put on, now makes 393 hp/377 tq. This is my daily driver.

The restricted 383 had instant low end power, which was neat, then got boring up to the shiftpoint. Now with the cam+exhaust, after the initial thrust from the converter is done, the motor screams up to the shiftpoint.

With a 60 rwhp/ 30 rwtq gain, I thought I would have major traction issues with worn tires at 9,000 miles. As it turns out, this is not the case at all. I still have yet to get a set of cnc'd heads and a FAST 102. It will be soon.

This description is exactly what you are saying, I know, but to answer the question, I love the max effort build. I definitely prefer it over the instant torque build. I really like how the cam smooths out the power delivery and keeps pulling hard to the end. Plus, you'll get more of those "validation nods" by others from the sound of that wicked cam.
________________________________________
01 Firebird Formula A4, cloth int, t-tops
Built by Next Level Performance, Orlando, FL
Trans built by Transmissions Plus, Kissimmee, FL

Motor : Balanced & blueprinted 383ci, 11:1 comp, 6-bolt main, windage tray, forged eagle rods, forged mahle pistons, forged crank, '11 CTS-V oil pump, Magnum 5/16 pushrods, dual valvesprings w/ti retainers, 42 lb inj, LS6 intake, '02 ZO6 heads, competition valve job, Comp Cams 230/236 114+4 XER, K&N induction, 255 lph fuel pump, American Racing 1-3/4" LTs, 3" y-pipe high flow cats, 3" manual cutout (which stays open for all eternity)

Driveline : FTI 3500, built 4L60E, big trans cooler, PST 3.5' driveshaft, 1350 yoke, Strange S60 4.10

Suspension : BMR k-member, BMR upper&lower front CA, BMR rear lower CA, adj torque arm, panhard bar, stock struts

Running NT555R 315/35R17 on the back

Dynos in at 393 rwhp / 377 rwtq

Tampa Tuning

iTrader: (2)

Depends how you drive the car, but id go for the 475 torque.

s346k

iTrader: (4)

i'd go with the 408. has more potential.

Philip Pugeau

You'll probably do what most of us would do. Get the bigger motor and have fun with that torque. When you get bored with it, build the top end!

racerfox

iTrader: (4)

trq wins races not so much hp

lemons12

iTrader: (71)

408 is the clear choice.

itsslow98

iTrader: (18)

Why not do a 408, sell the 243s and ls6 intake and do an ls3 top end for the time being youll come out even and have better flowing heads.

lemons12

iTrader: (71)

BOOM...

I have less than a grand in my ls3 top end.

30th t/a

iTrader: (51)

I looked into this option. I always had the mind set of all or nothing, either stock heads/LS6 intake or go all out with some TFS235s/FAST 102, when I could afford it. The LS3 heads/Intake woud be a mid grade build, but I see your point exactly, the stock 243s/LS6 intake/stock ported TB could be sold and the money could buy me the LS3 top end.

I also dont like how the LS3 heads have those huge intake runner's. I like that snappy throttle response & low end power and always thought that the car would feel slugglish with the LS3 topend, but then again its a freaking 408! it should make pently of low end with the LS3 topend, hell that might be a good thing running around with 3:90s & street tires (for now).

Im going to look more into this option

ScreaminRedZ

iTrader: (3)

50 hp > 25 tq

That said, I would go with the 408 since it will be easy to upgrade it down the road.