coldkillinTA

iTrader: (6)

Im dropping an LQ4 6.0l in my truck and I'm wondering If I put some 241 heads on there with no milling what will my CR be with the stock gaskets or with other aftermarket gaskets?
thanks in advance!

12secSS

iTrader: (30)

It would be around 10:1. I would keep the 317 on there, they flow better then the 241s. Unless you either do not have the 317 heads, or they are the iron (1999-2000) version?

sroach20

iTrader: (31)

you could go with 243s or get the 317s milled. im going to get some 243s for my lq4.

coldkillinTA

iTrader: (6)

The 243s are the LS6 heads correct?

Also, are you recommending the 317s over the 241s only because flow? do the pro's of the 317s outweigh the pro's of the 241s therefore giving me more power?

thanks

sroach20

iTrader: (31)

the 243s are ls6 and ls2 heads. yes the 317s will outflow the 241s. people have trouble getting rid of the 241s for a reason, they dont flow as well as the 243s, 317s, and now the l92s..

sroach20

iTrader: (31)

if you want to raise your compression for cheap, just mill the 317s.

coldkillinTA

iTrader: (6)

Well the LQ4 that Im getting is an early 2000 build so it has the iron heads. How much better do the 317 heads flow over the iron ones?

Also, what will happen if I used my heads off of my 4.8? Arent they the exact same as the 5.3s? thanks!

12secSS

iTrader: (30)

The 317 heads are similar to the 243 (LS6/LS2) heads, but with a larger 72cc chamber. The 4.8L and 5.3L heads are the same. Factory casting of the 4.8L/5.3L do not flow as well as the 243/317 port design. You can find 317s easily to replace the iron heads, and as mentioned just milled them to boost your CR. The 317s are worth it over the stock 4.8L/5.3L and 241 heads.

coldkillinTA

iTrader: (6)

So it wouldnt be worth saving the cost of buying 317s to just keep my stock casting 4.8s?

sroach20

iTrader: (31)

see if someone will trade your 4.8 heads for some 317s. they normally go for around the same price.

NemeSS

iTrader: (127)

4.8/5.3 do not flow as well as the 241's let alone the 317's
for what it will cost to buy used 317 and have them rebuilt,
u will be in the $ range for brand new set of ls6/ls2 243 heads
assembled with stock valves and yellow springs, less than 500$
for heads, stock truck intake will bolt right up to 243 heads
add ls6 z06 cam and it should make for a nice pull motor

coldkillinTA

iTrader: (6)

I know my heads (4.8) dont flow as well as the 241/243/317s, but will the increase in compression benefit more than the flow of the others??

ArcticZ28

iTrader: (14)

This debate has been around for a while - compression vs airflow. I believe the general consensus is the airflow. There is a much lower limit of compression versus how much air you can pack into a cylinder.

ls1leadfoot

iTrader: (1)

so 64cc heads and .040 gaskets would make a lq4 with factory dish pistons what comp.????????
need this info for a sts kit

m8w6r77

how much can you mill the 317's for lq4. the c/r is like 9.4:1. trying to get to at least 10:1

coldkillinTA

iTrader: (6)

I would like to know as well.

sroach20

iTrader: (31)

that all depends on the cam you are using.

m8w6r77

i am going to run a asa cam.

coldkillinTA

iTrader: (6)

Well what about a stock LQ4 cam and a 224/224 .581/.581 114 lsa

coldkillinTA

iTrader: (6)

Nobody can help?