Horsepwraddict

iTrader: (12)

Feel sorta stupid asking this, but im wondering what the tubes ontop of the valley cover on my 5.3 are? Their is one coming from each end of both heads and they merge together into one at the front of the motor. My guess is to heat the intake some, egr or some sort of air tube?

Can i plug them? Its a carbed motor and they led to the throttle body, which i obviously dont have anymore. Thanks in advance.

jmm98LS1

iTrader: (28)

Those are coolant crossover tubes, best to leave them alone.

Horsepwraddict

iTrader: (12)

...im sensing some sarcasm.. lol....does any coolant actually flow through them or should i block them off.

Ericbigmac83

iTrader: (19)

leave them be

and when you take them on and off put the seal on the right way othewise coolant will leak out. and you'll scare the **** out of yourself as you think youre about ready to fire up your new motor but then you see coolant leaking everywhere....

Horsepwraddict

iTrader: (12)

i cant find anything in alldata about the purpose/function of them. Im a little confused, how can i leave it be and coolant not come out of the open end of the line.

Sorry if im just missing something.

Ericbigmac83

iTrader: (19)

there should be a hose from there going into your tb, and from the tb to the radiator. look up throttle body bypass

Horsepwraddict

iTrader: (12)

thats my problem. im using a carb intake. i will look it up thanks

00ssmg

iTrader: (4)

Use A Capped Hose And Just Cap It Off That Way You Dont Have To Worry About Any Coolant Issues And Can Just Leave It Alone

Horsepwraddict

iTrader: (12)

thats what i originally wanted to do but lots of the tb bypass threads have said thats a bad idea. Have you done it?

Horsepwraddict

iTrader: (12)

im just going to make a T and run it into the upper radiator hose. Thanks for the help guys.

jmm98LS1

iTrader: (28)

From the factory, those coolant tubes run into the throttle body and then to a small fitting on the radiator right by the cap. Since you're going carbed, just run a 1/4" coolant line from the coolant crossover tubes straight to the small fitting on the radiator, effectively bypassing where it used to run through the throttle body. Lots of EFI guys do this as well to keep hot coolant out of the throttle body.