View Full Version : Could someone list the specs of the 1970 454 LS6?

03-03-2005, 07:53 AM
Could someone list the engine specs for a 1970 454 LS6 engine.

Like the true compression?
Did it have forged domed pistons or flat top?
Cam size duration and lift?
Solid or Hydraulic lifters?
What type of head (open or closed chamber) and valve sizes?
Carburetor size?
What type of intake?
Please list any other important facts about these engines.

Thanks guys.

And does anyone know the HP/Torque of these engine?

03-03-2005, 11:41 AM
:3gears: :seizure: Rated HP: 450@5600
Rated TQ 500 lb/ft @3600
Comp Ratio: 11.25:1
Carb: Single Holley 4150 800 cfm
Cam: 316/302 .520 Intake/Exhaust
Mechanical Lifters
Valves: Intake: 2.19, Exhaust: 1.88
Forged steel crank and forged aluminum pistons, don't know whether they were domed or flat top...

Hell of a machine to drive off the showroom floor. Supposedly ran 13.44@108 on street tires. :eek:

03-03-2005, 02:10 PM
Wasn't 13.44 smoking the Goodyear Polyglass tires for the first 1/8th mile?

03-03-2005, 02:11 PM
Despite the infamous "under-rated for insurance" tale that goes along with anything over 200 hp from the era, the "450 hp" rating was very accurate. If you're familiar with the "Benchmark LS-6" car, an original unrestored 19,000 mile black LS-6, when the engine was out for detailing/inspection a few years ago, in stock trim with all of the smog equip. it dyno'd at 452hp at the flywheel. With ONLY swapping on headers and a 1" carb spacer, it made 512hp.

Those manifolds really choked off what the big Rectangle-port heads were capable of. :eek:

03-03-2005, 02:40 PM
Thanks for the information guys!

Fuelie Fan
03-03-2005, 06:52 PM
That's pretty cool about the before and after. I wish there were more tests like that, especially on combos like original 302's, which people swear made 100+ more hp than they were rated at.

03-04-2005, 03:40 AM
I had the pleasure of doing a bunch of LS 6 cars. Back in the late 80, early 90s, I worked with some guys that specialized in LS 6s. In our hay day of muscle car business, before the bubble burst the first time. At one point we had 14 legit LS 6 cars in stock. I worked on everyone to some degree. Some tune ups, detailing, others full on concourse restos.
I had a chance to do a car for a local doctor we took to the dragstrip with a set of 10" slicks, he was scared, I had to drive damn it. We ran it bone stock, this is in 1990, it went low 13s, 13.08 being the best if memory serves. We then put 2" headers, a 850 DP I worked over a bit, on top of a torquer intake, We also put Cragers on Mickey Thompson Indy profiles for a true retro look, trying to make it look like what you would see in 1970. We put the slicks back on it, went back to the track and went 11.70s.
According to the math, it would take just north of 500 HP to propel that heavy boat to those speeds, so long story short, yes they could easily be unleashed.
A little head porting to the stock heads and roller cam, and a LS 6 can easily go north of 600 HP, with no work to the bottom end. And will stay together.
You have not lived until you hear the sound of a bone stock LS 6 motor at 7000 RPMs just daring you to pull the next gear!