jks67ss396

iTrader: (1)

Hey guys,

Im looking for some clarification on what size bolts i need for the rear crossover plugs and the front crossover pipe.

Heres some info i found here

LS1 rear coolant bolts (on back of heads) (HFH m6x1x30) = 11516425 (formerly 11514008)
LS1 coolant bolts for front pipe = 12561089
LS1 coolant crossover pipe = 12562169

So are the bolts for the back plugs actually different between the front and back?

And, are these part numbers actually correct? 11516425 and 12561089

And, cant you guys tell me the bolt sizes? m6x1x30 on back? and on front?

thanks

MeentSS02

iTrader: (11)

The front bolt size is correct - I just measured the stock ones on my LS1 the other day, and that's what I came up with. I've never looked at the rears on mine though, so I can't say for sure if the bolts (or studs as they are on mine) are the same back there, but I can't imagine them being different seeing as how the heads are mass produced - it would make more sense to make the hole diameter, depth, and thread pitches identical front and rear.

jks67ss396

iTrader: (1)

Hey Steve

So, the front is m6x1x30?

i cant imagine front/rear being different either...

thanks

MeentSS02

iTrader: (11)

I'll double check the measurements when I get home, but it was definitely an M6 x 1.0, and it was pretty long, so the 30mm length looks correct to me.

jks67ss396

iTrader: (1)

thanks man

ive got 3 30mm bolts and 4 40mm bolts. (measured total length.. thread + head)

might be missing one of the 30's and the 40s look like they will work, but im sure ill need them for something else...

again, thanks for all your help

sjsingle1

iTrader: (1)

used 30mm front and back on mine

jks67ss396

iTrader: (1)

30 mm under the head or total overall length?

thanks!

sjsingle1

iTrader: (1)

all bolts are measured under the head

jks67ss396

iTrader: (1)

just making sure

thanks!

MeentSS02

iTrader: (11)

I measured 34mm under-head length on the stock studs, so 30mm will be a little shorter, but should still have plenty of thread engagement.

Paul Bell

iTrader: (9)

The front and rear threaded holes in the heads are identical.

Retain and use the coolant tubes to the back of the heads. The rear cylinders can use all the cooling help they can get.

jks67ss396

iTrader: (1)

its actually an lq4, so i have the plugs in the back and the pipe up front

sjsingle1

iTrader: (1)

you can put a LS6 pipe in the back........i did

jks67ss396

iTrader: (1)

does it work with the lq4 truck intake?

sjsingle1

iTrader: (1)

i am sure it has the same clearances as the LS1 and LS6 intake..........no?

sjsingle1

iTrader: (1)

jks67ss396

iTrader: (1)

so wheres the steam bleed off in the back? in there a line that goes up to the radiator/pump/intake that i cant see in the pic?

sjsingle1

iTrader: (1)

it simply goes from left head to right head......did not bother to hook it into the front line......figured it was better than block offs