I tried a search, no answers.

Motor is a iron 383 (3.9" bore). No boost or nitrous planned.

Are expensive aftermarket heads (PRC 227, etc.) overkill for a heavy truck motor that will not see over 6000 rpm?

I want low end power, but would still like good peak power at 6k.

I'm not worried about spending the money if the gains are solid. If not, what is a good alternative?

Thanks!

 

I would think you'd want something smaller like a 210-215, and mill the heads a bit to get the compression up.

 

It's never overkill, with the right compression ratio, tune and cam you should see a good bump of low end torque.

Though you can achieve most of that by a cheaper head with some work, the real benefits of those will be more up top.

 

You bet, I have AFR 210's on my 2500 4x4 and constantly haul payloads around 3000 pounds and not only do I have way better of throttle response but get at least 1.5 mpg better to the gallon.

 

Wow fuel economy gains...that oughta be nice in a 2500 series truck!

Have you considered building a diesel for that truck of yours? Fuel economy, cheap horsepower, and gobs of torque. Cummins 12v swap FTW

 

No, I like the power to engine weight ratio that this 6.0L has. There is a curvy road that I travel a lot where faster diesel pickups can't keep up with me b/c of their heavy front end not wanting to stay on the road.

 

If you want aftermarket heads, Trick Flow is what I would look at. They will provide everything you want. Set them up with a good cam and you will get some KILLER torque.

Otherwise, a good set of 243s will get you all you would need honestly.

 

I would consider ported stock castings if budget was a concern.

 

I would say AFR 205's (now 210's) on a 383...

I'm doing a similar build for my truck only it will be a 408 with Mamofied AFR 215's.

 

What's the original head? I know on my 5.3 it came with 243's from the factory.

 

Thanks for the replies.

I'm planning a cam and tune by Pat G after I get it running. CR will be 11.3ish.

haha, don't want to mess with diesel. this engine will not be in this truck forever. Maybe a '69 camaro in a few years...

Original heads on the LM7 were 706's. Heads on the LQ4 currently in the truck are 317's.

Not worried about gas mileage.

Budget is not the main concern, however I don't want to spend money needlessly. If a good set of ported 243's (half the price of 227's) will result in only a 5-10hp difference, the 243's are probably the way to go. If the 227's will get me 20+ over the 243's, I'd go with the 227.

 

Look into A.I.s stuff for stock castings. They have some pretty impressive stuff going on over there. Here are some 243s I sent to them.

https://ls1tech.com/forums/generatio...-cnc-work.html