427 or 6.0

[JEM]

Originally Posted by menace121978

obviously i'd go with the new technology myself... i honestly believe that anyone who is voting for the old school big block hasnt had the opportunity to own or drive the new generation of muscle. i'll never go back

I'm kinda thinking that with a late-model aluminum 6.0 and some attention to component choice and location it might be possible to build a '66-72 that's not too far off 50/50 weight distribution.

Not only are the newer engines far lighter, the whole FEAD including alt, AC compressor, PS pump, etc. doesn't weigh a whole lot more than an old A6 AC compressor by itself, never mind bracketry, pulleys, etc.

[okieraptor]

Ok for those of you running the 6.0's. Heard a lot about 20mpg's. Really? I know a couple of guys with vmax's that are pullin the same mpg's as my titan, 15! How are guys gettin 20 out of them. I know they are detuned from the factory but that was the help fuel mileage not hurt it.

[68GMCCustom]

has a LOT to do with your "cruise" rpms. Keep 'em below 2200rpm or so and your OK...higher and down goes the economy.

Our TBSS has 4.10's and only gets 15-17 or so on the highway.

[menace121978]

has alot to do with how ya drive them... i'm at 13.8 in the goat. my buddy gets consistant 20-22mpg. i drive the heck outta mine stop light to stop light everyday.

keep in mind the trucks weight also... the newer style ecsb is alot heavier than a square body.

[okieraptor]

Very true I'm the same way. "STOP" means spin tires on pavement lol. I build them or by them to drive not put-put around.

Aren't the new truck 09-10 truck 5 or 6 speeds. Would that be the 4l85's. Anyone swaped in one of those yet?

[JEM]

Just wish GM would get that 4.5 Duramax out the door.

That'd be one hell of an interesting engine in, say, a '69 Camaro, a '70ish truckarm pickup, a '75 Nova, an '04 CTS-V if the smog Gestapo would permit...same package size as an LSx motor, weight close to an old iron smallblock...

[JEM]

Originally Posted by menace121978

has alot to do with how ya drive them... i'm at 13.8 in the goat.

My M5 is quicker than that...

Seriously, though, much as I love the Bimmer when it comes to dollars-per-HP there's not much that can touch the LSx motors.

[okieraptor]

I think he meant 13.8mpg. At least that's how I read it.

[bigblock73]

yes, we're talking mpg, not et's...LoL

[menace121978]

yes it was mpg!

[68GMCCustom]

our TBSS runs 13's...with a 395hp/400tq LS2. If I added blah blah blah... 12's. And I expect my truck when finished to run 12's for starters.


...Oh yea...we were talking mpg's. I can get worse then 13.8mpg in it if I drive it hard...more like 12's.

[okieraptor]

If you get to the 12's that will be one sick truck.

[68GMCCustom]

its all going to depend on the traction. w/500+hp 11's are possible actually.

[Jim85IROC]

Originally Posted by 69BBsuburban

I've driven BRAND NEW Corvettes, etc....
I still prefer the brute force and crudeness of my old jalopies....it's more than just the performance....there's a certain style and "coolness" factor no newer, plastic car can ever dublicate. Just my old school .02.....I'm an oddball

Brand new corvettes are a poor measuring stick unless they've had an aftermarket tune to eliminate the torque management. In bone stock form, those cars feel neutered.

Take a look on ls1tech at some of the dyno graphs of some of the modified 6.0s... they've got a torque curve that would embarrass some big blocks.

[glock35ipsc]

I used to be a died-in-the wool SBC and BBC fan. But after having put several thousand miles on my 85 with the 5.3, I just don't see myself ever building another SBC or BBC.

As for a coolness factor, most people are expecting a decked out small or big block to be living under the hood. When they see something that's not expected, that's when the "wow, that's cool" starts rolling off their tongues! I can only stare at a run of the mill big block for so long......

Originally Posted by okieraptor

Ok for those of you running the 6.0's. Heard a lot about 20mpg's. Really? I know a couple of guys with vmax's that are pullin the same mpg's as my titan, 15! How are guys gettin 20 out of them. I know they are detuned from the factory but that was the help fuel mileage not hurt it.

I've been getting 20 mpg fairly easy during my commute to/from work, and it's not all driving miss daisy. The worst I have recorded with a heavy right foot is 17 mpg.

IMO, the factory detunes them more for preservation of the drivetrain rather than max mpg (see Torque Management). Simple tuning (real, in-depth tuning, not a hand held programmer) alone can gain a great deal of mileage. My 85 is about 1100# lighter than my 2wd 03 ECSB was, so that helps with the mileage. Plus I did a dyno tune with mine, so we were able to tune fuel and timing curves to maximize performance and mileage.

[68GMCCustom]

If funds aren't an issue....I suggest just going with the LSX 454 and add your choice of induction and spark control system. We're talking 620hp/590tq to start with. Just add your choice of OEM EFI controller and harness, PRO FLO, FAST EFI, Megasquirt, etc. and your set. Or of course you can run a carb like I plan on.



LSX454-Crate-Engine

LSX454 TECH SPECS
Part Number: 19244611
Engine Type: LSX Series Gen IV Small-Block V-8
Displacement (cu in): 454 cu in (7.4L)
Bore X Stroke (in): 4.185 x 4.125 (106.3 x 104.8 mm)
Block (P/N 19243172): LSX cast-iron with 6-bolt. cross-bolted main caps.
Crankshaft (P/N 19170391): 4340 forged steel
Connecting Rods (P/N 19166964): 4340 forges steel
Pistons (P/N 19166958): Forged aluminum
Camshaft Type (P/N 19166972): Hydraulic roller
Valve Lift (in): 0.635" intake / 0.635" exhaust
Camshaft Duration (@0.050 in ): 236deg intake / 246deg exhaust
Cylinder Heads (P/N 19201806): Aluminum LSX-LS7 port; with "as cast" 70cc chambers
Valve Size (in): 2.20 titanium intake / 1.61 exhaust
Compression ratio: 11.0:1
Rocker Arms (P/N 12579615 int): Investment-cast, roll trunnion
Rocker Arms (P/N 12579617 exh): Investment-cast, roll trunnion
Rocker Arm Ratio: 1.8:1
Recommended Fuel: 92 octane
Maximum Recommended RPM: 6500
Retuctor Wheel: 58X
Balanced: Internal

[Cherub]

i vote for a 427 lsx mmmmmmmmm

[BigBlocksRule]

That LSX454 will put out a damn sight more than 620hp. I've seen 6.2L based 426's put down those numbers with a 23X/23X cam, lope was noticeable but it wasn't a fender shaker by any means. Induction was an L76 injection, outta the box.

I think the best bang-for-the buck, though, is a stroked 6.0L iron block with good cathedral port heads and injection. I like the 4L80E tranny a lot more than the 4L60E/variants and the factory computer will control both the engine and tranny.

That iron block will take a ton of boost or spray, take your pick.

[okieraptor]

There's a guy here in town that has a built up iron block 6.0. It doesn't impress anyone. A bone stock z06 wlked it by two car lenghts. We've come up with its way over camed with the heads mildly ported and stock intake. There is also a guy with a scsb with a 5.3(so I'm told) with a big cam that will run with in two truck lengths of the camaro 6.0. I know both were tuned somewhere down in Dallas.

My uncle still won't come off his truck so I found a crew. Having kids this will prolly work out better anyway.
Plans: 6.0/4l80e, slammed, 22's, leather insides.
6.0 will get heads( wich ones??????) Cam(????????) Intake( probly a fast 90mm.) Any input will be apreciated. I think ill say over 450hp up to about 525hp. But has to be able to drive everyday every where with good milage.

[68GMCCustom]

Best deal for high flowing heads for a 6.0L are the L92 or LS3 heads.

[Jim85IROC]

Originally Posted by 68GMCCustom

Best deal for high flowing heads for a 6.0L are the L92 or LS3 heads.

Yup. Under $700 for a pair of LS3 heads, brand new right from GM. How can you beat that?

I'm assembling a 6.0-based 402 stroker with LS3 heads & intake for my IROC. With a 230-ish cam, I anticipate 500+ RWHP with a fat torque curve to match... and 20+ mpg.

Let's see a big block do that.

[okieraptor]

Originally Posted by Jim85IROC

Yup. Under $700 for a pair of LS3 heads, brand new right from GM. How can you beat that?

I'm assembling a 6.0-based 402 stroker with LS3 heads & intake for my IROC. With a 230-ish cam, I anticipate 500+ RWHP with a fat torque curve to match... and 20+ mpg.

Let's see a big block do that.

wow keep me updated on this. Mine won't be a 402 but these ls3 heads sound like a good deal. Very interesting....