[Aussie Mike]

Those figures quoted are all flywheel numbers where as the Dyno results were rear wheel.

As a rule of thumb what the engine produces at the flywheel is what it will make in HP at the rear wheels.

For example the 347 windsor in my Pursuit made 196KW at the rear wheels at a dyno day last year. This equates to about 262HP at the rear wheels (KW to HP is x 1.34). The Pursuit is suposed to make 250 KW at the flywheel standard but mine has a cat back exhaust on it so is probably making a bit more.

Those were some impressive number out of your motor Stiffy regardless of the badge on it.

The Commodore guys have been getting as much as 250KW at the rear wheels out of a stock unopened LS1. Just careful tuning and a good exhaust and cold air intake. A change of cam can easily push that into the 270-300KW depending on how lumpy it is. I think part of the reason is the LS1 cylinder head design. They flow huge numbers straight out of the box.

Cheers