BrianC98Z28

iTrader: (11)

I tried to find some stock ls1 head #s but couldnt... I was just wondering how much better they flow over ls1 heads? Thanks

Brian

Xtnct00WS6

iTrader: (8)

Intake LS1 LS6

.200" 137 156
.300" 187 204
.350" 207 225
.400" 223 243
.450" 228 257
.500" 237 268
.550" 242 275
.600" 243 278

This is what I have from an excel spreadsheet I downloaded a while back.

staringback05

iTrader: (8)

what castings are those ls1s?

Xtnct00WS6

iTrader: (8)

That's all the info I had. It just said LS1 and LS6, so it's at least 243 for the LS6. I'm not sure for the LS1. I could be any LS1 casting (241, 853...)

c5_ls1_6spd

iTrader: (-1)

what's the difference between the 241 and 853 castings?

GuitsBoy

iTrader: (4)

Sand cast vs. SPM. The port design is the same IIRC.

xfactor_pitbulls

iTrader: (16)

Your numbers are slightly high for each head. The ls6 casting does not hit 204 @ .300 for sure. More like 230 up top for the LS1 head and 265-270 up top for the ls6.

Brandon

c5_ls1_6spd

iTrader: (-1)

so does the 241s flow more than the 853s or do they flow the same?
what's SPM?

xfactor_pitbulls

iTrader: (16)

Slightly. Basically its just die casting.

Brandon

Photochop

iTrader: (74)

I heard a rumor a while back that the 241 intake runner was slightly larger than the 853s

GuitsBoy

iTrader: (4)

I think its the 853 that was slightly bigger than the 803s

PREDATOR-Z

This is from Thunder bench:

LIFT - 241 -LS6
.050 _33.8 _33.0
.100 _63.6 _65.2
.150 _96.7 100.7
.200 135.2 138.0
.250 166.3 167.7
.300 191.0 192.7
.350 210.4 213.1
.400 223.2 230.0
.450 230.3 243.1
.500 226.5 254.1
.550 226.5 257.0
.600 230.6 238.0
.650 234.6 240.1
.700 237.8 242.3

Cgillies86

iTrader: (1)

What year cars have the 241 castings?

GuitsBoy

iTrader: (4)

Mid year 2000 - 2004 ls1s.

allngn_c5

iTrader: (3)

Who even cares, just go get some AFR's
My stock LS1's were horrible. The AFR's
solved everything.

Jon2kZ

iTrader: (5)

Yeah my 2000 has 241, 6/00 build date

Are you really looking for numbers? or would a better question be which are the best flowing factory heads I can get for a decent price?