This new HP3 is going in my Nordic. Here is a pic of what's under the valve covers.
It exists, there are 12 left that are new.

this one is a MOD 3. It dynos at 559 at 5400 540 tq

Never heard of those ! Where are the others new ones?

Very cool.

Just make sure you stay on top of the valve springs. From my memory the valve to piston clearance was TIGHT.

These motor are all dyno'd at the factory and leave perfect.
There are zero issues only a few articles that made that claim the tolerance was tight. They run flawlessly.

there are only 12 left

There are 12 left.

Clearance to tight because they're a truck engine, who is reworking these to open up clearances ?

LOL every BBC is a truck engine.

Search HP3 here and Google. These are very specially built engines by Innovation marine for GM Marine division.

These motors out performed the Blue top 500 and 525 and half the cost. Gen 5 and Gen 6 motors are ancient tech.

ya you keep believing that, so the L-88 and ZL1 427's are truck engines....your knowledge is impressive pics of the valve springs are also very impressive...........good luck with your truck engine

F2,

As I understand it, GM purpose built these engines as marine engines, not as "truck" engines. They essentially did everything that Merc should have done to the 8.1 truck engine during marinization. It's everything the 496HO SHOULD have been. And they performed so well that Merc threw a hissie and bullied GM into discontinuing them.

Thanks. Brad.

Brad,
Do you think you would of been ahead fiscally if you bought one of these motors and bolted on your Procharger instead of rebuilding what you have?