Why aren't L5P heads on older gen trucks?

Dozerboy

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Another thread got me thinking about this again. My understanding is one reason the L5P spool so well is because of the heads. I really figured by now people would be machining L5P heads or have their own castings with an L5P style ports. Is there really just not that much of an improvement in flow on the L5P or what? Seems like a pretty "simple" upgrade to me with a lot of upside.
 

Bdsankey

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Quite a few people have done this swap, the part that is a bit painful is the need to custom make a y-bridge, pushrods, up-pipes, and a few other things.

I know the few that have completed it are very happy with it.
 
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gmduramax

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Quite a few people have done this swap, the part that is a bit painful is the need to custom make a y-bridge, pushrods, up-pipes, and a few other things.

I know the few that have completed it are very happy with it.
Wonder if there’d be interest if someone put a kit together 😉
 

Chevy1925

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Yeah when i looked into this, its not very simple. Injectors were probably my biggest hold up since i didnt want to make them work and i had 100 overs already
 

Dozerboy

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Quite a few people have done this swap, the part that is a bit painful is the need to custom make a y-bridge, pushrods, up-pipes, and a few other things.

I know the few that have completed it are very happy with it.
Yeah I guess I can see where that would make it a little less feasible. I wonder if Fleece or anyone has ever looked at making older head that bolts on but has the flow of a L5P. You wouldn't think it would be all that hard since the design is pretty much there minus making so it "bolts" on. I'm probably over simplifying it in my mind though. Maybe it would choke it down too much if you made it bolt on...

Maybe when I win the lottery I will have L5P heads on my LBZ. Of course that just means it's gonna spool that much faster so I'm just gonna make more TQ and break shit faster. 😅
 

2004LB7

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Yeah I guess I can see where that would make it a little less feasible. I wonder if Fleece or anyone has ever looked at making older head that bolts on but has the flow of a L5P. You wouldn't think it would be all that hard since the design is pretty much there minus making so it "bolts" on. I'm probably over simplifying it in my mind though. Maybe it would choke it down too much if you made it bolt on...

Maybe when I win the lottery I will have L5P heads on my LBZ. Of course that just means it's gonna spool that much faster so I'm just gonna make more TQ and break shit faster. 😅
If you win the lottery, you might as well put an L5P block and rotating assembly under those L5P heads too 😛
 
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1FastBrick

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Yeah I guess I can see where that would make it a little less feasible. I wonder if Fleece or anyone has ever looked at making older head that bolts on but has the flow of a L5P. You wouldn't think it would be all that hard since the design is pretty much there minus making so it "bolts" on. I'm probably over simplifying it in my mind though. Maybe it would choke it down too much if you made it bolt on...

Maybe when I win the lottery I will have L5P heads on my LBZ. Of course that just means it's gonna spool that much faster so I'm just gonna make more TQ and break shit faster. 😅
The tooling cost is very high. Look at the Edelbrock Duramax heads and how long it took to get a product to market. It seems like they have droped any further work since the buy out too... They no longer cast heads for AFR Either after the buy out. AFR picked up there tooling and took it to Buddy Bar.
 
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56taskforce

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I waited a long time for Edelbrock to release LBZ-LMM heads. I got an in development response for 2 years then they quit responding. My hopes were that it was taking so long because they were integrating the L5P ports into them since the L5P came out just after they released LLY and the LML.
Well it was a nice dream.🙄
 

PureHybrid

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I waited a long time for Edelbrock to release LBZ-LMM heads. I got an in development response for 2 years then they quit responding. My hopes were that it was taking so long because they were integrating the L5P ports into them since the L5P came out just after they released LLY and the LML.
Well it was a nice dream.🙄
Be better off contacting Brodix, last I knew they are one of the only head companies that are NOT owned by a big conglomerate
 

1FastBrick

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I waited a long time for Edelbrock to release LBZ-LMM heads. I got an in development response for 2 years then they quit responding. My hopes were that it was taking so long because they were integrating the L5P ports into them since the L5P came out just after they released LLY and the LML.
Well it was a nice dream.🙄
The Edelbrock heads sure looked promising....
 

TheBac

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I guess Id have to see side-by-side comparison photos of the L5P heads to older ones to see what you guys are talking about.
 

PureHybrid

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This one makes me question the benefits

View attachment 128606
It's deceiving because the L5P doesn't appear to be cut in the center of the valve seat. Just based on that picture the extra flow comes from a better short side radius and the roof isn't going uphill right before the pinch. The giant opening at the intake doesn't help anything, most flow gains or losses are determined within 2in of the valve
 

Dozerboy

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I know there is a massive cfm gain to L5P heads. You cant put a s472 on a 2016 and older, run a G converter and build 25psi of boost at 1500rpm. Ive seen that with my own eyes and its fucking awesome lol
Ya I called BS on them spooling 472 (or 476 I don’t recall) until I seen one do it. Of course 4 set of pistons later that guy was done with messing with the L5Ps.