Would there be any upside (other than the bump in CR) or do the Iron LQ4's still outflow the LS1 heads ????

And.....how about the LS1 heads with a Comp 212/218 .558/.563 114lsa XE High-Lift cam on a 6.0 block ???.....

 

The 6.0 heads are aluminum, not iron. The 6.0's still outflow the LS-1's. I wouldn't swap down. Espeacially stock for stock. If anything, look into a ported 6.0 head.

 

99-00 6.0 heads are IRON !! (I KNOW...I OWN two pairs of them), and according to most on here do not flow as well as the aluminum #317 castings......I HAVE a set of #241 LS1 heads that I would like to use if the flow #'s are similar or better than the IRON LQ4 heads

 

Hello Yelo. I think its a good swap.

I've got a set of mildly hand ported 317 castings if you are interested.

 

Alrighty, I don't know alot about the older truck stuff. If indeed the truck heads flow similar to the LS-1 heads, you might be on to something. You'd have the same flow with less intake runner volume. This will = more velocity and in turn more power. You'll also get more compression which will help to. Best thing to do is find out about the flow diffrences between the 2.

 

THAT'S what I'm trying to find out here !!!!

and Big Tex.....don't EVEN say it

 

OK...here are some hard and fast flow numbers for STOCK LS1 heads and STOCK 6.0 heads (I raided a couple of other posts for this info)

STOCK LS1 head (from the Chevy High Performance Website)


STOCK 6.0 heads (courtesy of Jason99ta...even if he doesn't realize it )




To me it appears that the LS1 head outperforms the 6.0 head by quite a large margin at low and high lifts (mid lifts it loses a little to the 6.0)

 

It is always best to compare flow numbers from the same bench. So, here are the flow #s from a set of stock LS1 castings (853) I flowed awhile back.

 

You have to remember that the trucks need the big mid lift numbers to pull around a heavy truck. If you sacrifice mid lift for more high lift numbers you may be disapointed. Personally I'd be looking for a good "cleaned up" aluminum 6.0 head. You'll probablly be more happy with the gains.

 

Jason....any difference between #241's and #853's ???

I would like to use the #241's I have for a couple of reasons.....I ALREADY OWN them, they will have a higher CR due to the smaller chambers, and they are ALUMINUM (ignore all of my previous posts about IRON guys OK)

I am also interested in doing a mild P&P job to these #241's I have....even without a decent port job they shoud still outflow the iron 6.0's.......correct ???

 

The "241" casting do flow slightly better. It is only ~5cfm, but it is definitely a better flowing casting.

The iron 6.0l heads flowed VERY similar to the 853 LS1 castings. The 317 6.0 aluminum castings were the heads I flowed above (6.0l flow #s).

Some minor cleanup work on 241 castings will work much better than the stock, iron 6.0 heads.

Jason

 

THANK YOU !!!

that was EXACTLY what I wanted to hear !!.....given the budget I am currently on the #241's are gonna be the head of choice

BTW...do you have flow-data for the iron lq4 heads ???....I know you said they flow VERY similar to the #853's but I'd love to see the numbers.....

 

Sorry, I wish I did. However, we had a hard-drive failure and lost flow #s for over 200 LS1 heads (including the stock #s) awhile back. The ones I had printouts of were the ones I posted above.