LS6 intake swap

[Sneaks]

I got a lead on an LS6 intake and fuel rails for a good price. What kinds of gain can you expect from just swapping out the LS1 for the LS6 intake? What else needs to be changed over from my '98, so that I can use the LS6 manifold? Is it worth the hour and a half or so to swap the manifold if I'm going to leave the stock LS1 throttle body?
Thanks, in advance, for your input.

[Cobra4B]

IMO not worth it unless you're going to do other mods and tune it. That said, you allrady have headers and an intake (I assume) so you might get 10 rwhp w/ a tune.

You'll have to tune b/c the injectors are larger, or you can just swap in the injectors you have now as you don't need larger injectors for your setup.

You'll have to upgrade your coolant tubes also.

[Y2Kvert4me]

LS1 and LS6 throttle bodies are the same, nothing gained or lost there. The single line LS6 fuel rail won't work on your car, assuming your 98 has the return style fuel system (2 fuel hoses connected to the rail).

The only additional thing you need to install the intake, are the small metal coolant lines/plugs that run between the heads and beneath the intake.

The GM part #s for these parts are as follows:

12602544 – Coolant Pipe (qty 1 )
12602540 – Coolant Plug (qty 2)

I can't say what kind of hp gain you'll see, maybe 5-10...but it is a much better intake than the LS1 and is worth swapping to, and will compliment any additional mods you may do down the road.

[Y2Kvert4me]

Originally Posted by Cobra4B

You'll have to tune b/c the injectors are larger, or you can just swap in the injectors you have now as you don't need larger injectors for your setup.

Injectors would be the same.

C5's and Z06's all used 28.8# injectors, with the exceptions being 1999 and 2000 model years...they had smaller 26.2# injectors.

His 98 should have the 28# stock.

[Cobra4B]

^ Thanks for clearing that up Tom... wasn't sure which years used the smaller ijectors. Good call on the return-style fuel system.

[Sneaks]

Originally Posted by Cobra4B

IMO not worth it unless you're going to do other mods and tune it. That said, you allrady have headers and an intake (I assume) so you might get 10 rwhp w/ a tune.

You'll have to tune b/c the injectors are larger, or you can just swap in the injectors you have now as you don't need larger injectors for your setup.

You'll have to upgrade your coolant tubes also.

Originally Posted by Y2Kvert4me

LS1 and LS6 throttle bodies are the same, nothing gained or lost there. The single line LS6 fuel rail won't work on your car, assuming your 98 has the return style fuel system (2 fuel hoses connected to the rail).

The only additional thing you need to install the intake, are the small metal coolant lines/plugs that run between the heads and beneath the intake.

The GM part #s for these parts are as follows:

12602544 – Coolant Pipe (qty 1 )
12602540 – Coolant Plug (qty 2)

I can't say what kind of hp gain you'll see, maybe 5-10...but it is a much better intake than the LS1 and is worth swapping to, and will compliment any additional mods you may do down the road.

Pretty much what I was thinking. Change out the fuel rail from mine now, and upgrade the coolant tubes.
We all know the LS6 intake breathes better, which is the main reason for the bump in power for the base C5's from 345 to 350.
Mainly just looking at down the road. Might as well pick it up now while the price is right.

[2ez 2spd]

I was thinking about doing this too do but just like the OP I didn't know what to expect. But now I see from this thread its better to wait on this until I get some more parts to go with it, that this alone will not make much difference. So thanks for the info that helps give me some direction.

[Cobra4B]

Actually the 350/375 ls1 has a LS6 block, different heads, different cam, LS6 manifolds (exhaust and intake), etc. vs. the 345/350 motor.... so its not just the intake.

[1TZSLO]

I picked my LS6 intake up for 280 and then the 3 parts from GMpartshouse pushed me to 300bucks, I couldn't pass it up either. March 15th my car is heading to the shop for install of lots of parts. pics and video will be posted on the 19th. Its a fairly mild upgrade on stock motor but with more goodies it doesnt hurt