Warning...PICS - heads stock vs. stage II

[herb101]

I was playing with my parts in the garage a little while ago (truck parts - come on people) and I decided to document the differences between the stock heads and the Stage IIs I'll be putting on. So here that is...

Cams - I was surprised that I could actually easily see the increased duration in the cam grind. These pics are crappy, but what you're looking for is the overall shape of the lobe, especially the narrow part on top. The narrower this peak is, the quicker the valve event. Slower event = valve open longer = more duration. I could also see a slight increase in lift as observed by the taller narrow part on the new cam, but it is a small difference.
Stock cam lobe:


Stage II cam lobe:


Here are the combustion chambers compared...
Stock:


and Stage II:


and the valves with a tape for reference...
Stock:


and Stage II:


Here are the ports, intake first, with the gasket for reference...
Stock:


and Stage II:


and finally, the exhaust ports, with a tape for reference...
Stock (note that the port is actually about 1-1/4" across - the carbon build up makes it look larger):


and Stage II:


Sorry about the book (but hey it's a picture book), but I thought this might be good info for anyone considering heads, but not really sure of what they'll get.

Enjoy,
Herb

 

[LIGHTNING LARRY]

Damn! I want a set of those heads. :rockon: :rockon:

 

[herb101]

Damn! I want a set of those heads. :rockon: :rockon:

Call Mark @ LFP and send $!! Mark said he'd match the price for others interested too. Exchange price was $1595 including cams.

Herb

 

[DSG03LTNG]

Great pics and info Herb!!

PM sent!!

 

[ChrisNelson]

That is mint. Thanks for showing us that...looks like I need to start saving.

 

[herb101]

Thanks for the props guys! :bowdown:

It's hard to drop nearly $2k and not see what your buying. I figured I'd help anyone else know what a Stage II heads is and how it differs from stock.

We all spend some serious coin on these trucks. It helps to justify the expense when you know exactly what to expect.

The thing that amazes me the most is how little everything is for the power these motor make. The stock exhaust port is only 1-1/4" across and the stock intake valve is only a little bit bigger than SBC exhaust valve (with good heads). Even the aftermarket bigger valves are small in comparison - any SBC powered vehicle on the road will have at least a 1.94" intake and a 1.50" exhaust valve. The new ones in my heads ate 1.78" and 1.452".

Herb

 

[Thunder Bolt]

Saweet!

 

[Sinister04L]

Great pics and info Herb!

 

[redz_02]

Thats what i said when i saw a set of 5.4 heads, comparing them to my LS1 stage2's the ports were tiny. That may be why changing cams to stock heads on the SOHC motors dont make much of a difference. With a g5x2, long tubes, and so on my LS1 jumped from 330 rwhp to 408 rwhp.

 

[fakesnake408]

Thanks for the pics and the info man.

 

[sharkbite]

Good pics! Thanks!

 

[Boostfan]

I will definately get a set of those in my future. Thanks for the post.