98SSdriver

I'm installing a LS6 405 HP crate engine in my 98 SS. Will a FAST 90 intake and tb be too much or should I go with the FAST 78?

Anybody out there who has done this on their LS6, any advise?

Thanks.
Fred

98z28chevy

Hi 98SS i have a 98z and i purchased a 04 LS6 from a Z06 i was wondering what type of PCV system u using? I went to GM and asked for a Z06 type pvc system said they didnt have one. Also if u need coil brackets for the centerbolt valve covers GM dealer sells them for 15 bucks each not bad. But i currently waiting on oil pan and Z06 intake i ordered from Gmpartsdirect.com not bad for the intake 388.00 with gasket kit and all. My 98z motor blew rod and destroyed the block and oil pan. Also how much HP u expecting to make with the LS6 with ur mods? i also have a Borla Catback exhaust i bought some Pacesetter long tubes with ORY.

co.6z28

iTrader: (1)

i would go with to fast 90 if ya got the cash. it will help you out down the road if you do cam,heads ect.

98SSdriver

98z28chevy -

I am not sure how much HP I'll make, but I'm starting at 405 at the engine. With the free breathing air induction, LT headers, borla, and I'm sending my ecm to MTI for tuning, depending on the intake/tb combination, it should make at least 450 hp at the engine (400 rwhp). Check out this LS6 article from GM High-Tech: http://gmhightechperformance.com/tech/0503htp_ls6/

My local Chevy dealership is doing the install for me. I got my info on the swap from "BandDirector". Here is his website with an excellent write-up on his LS6 swap: http://www.banddirector.cz28.com/index.html

This is how he solve the PCV question - "The only thing that won't bolt directly up is the driver side PCV valve. The LS6 driver side PCV valve runs under the intake and comes out right below the throttle body on the passenger side. I spent $ 3 on some hose and an adapter to route the PCV valve in a loop to send it back into the intake."

co.6z28

Since the engine died in my 98 I needed to do something quickly, since my loan, money is not the issue. If the fast 90 is not too much for the LS6, I'd like to go with it.

98z28chevy

Cool Thanks 98SS what PCV valve did u use? a 98 ls1 or a 02-04 ls6 valve? Are you gonna keep EGR and AIR system? i'm taking out the A/C , EGR and AIR things clutter up the whole engine bay. I got a pretty good deal on my 04 ls6 had to drive 4 hrs to PA to get it but it was worth every min.

98SSdriver

The EGR is gonna go since it is not on the LS6. The stock PCV should work with the re-routing.

Any other thoughts on which intake and tb to use, the FAST 78 or the 90? I'm leaning towards going with the 90.

98z28chevy

I would probably go with the 90 if u plan on going with a Super Charger or Turbo might be overkill without serious mods.

98SSdriver

98z28chevy
You're right on! I just ordered the FAST 90, fuel railsw/ fittings, and the NW TB from Speed Engineering. They have a super pricing deal going on in the Sponsor special section. Thanks Jim for the great pricing!

98z28chevy

hey 98ss so when u plan on putting ur motor in your car? Also if u plan on getting it dyno i would like to know what type of power u will be making.

98SSdriver

The Chevy dealership has already ordered the LS6. They'll start to work on it next week. I'm sending my Jet Hot LT's back to Jet Hot for re-coating. That will take about 2 weeks. I might have the SS back by the end of Aug or early Sept. After a break in I plan on getting it dynoed.

BandDirector Blk98ZM6

iTrader: (21)

Here I am Fred

I actually figured out how to run my PCV from this site's article:

http://www.ls1howto.com/index.php?article=18

The article is actually how to swap from the LS1 PCV system over to the LS6 style, but since the LS6 longblock already comes with everything already installed, all you need to worry about is near the end of the article where it tells you how to re-use your PCV valve with a little extra hose.

I've had my LS6 installed for over a year now, but I've only managed to put 2500 miles on it. I'm still running on the stock '98 tune and it's running fine, but as soon as I hit 3K miles, I do plan to have a dynotune to make sure I get everything I can out of my LS6.

98z28chevy

Cool hey Band hows it run with the stock tune i might have to run it awhile on a stock tune. Also do u have headers? i got Pacesetters LT's i hear with headers usally have to get a tune. Also i picked up my coolant tube that goes on under the intake. I got one that goes across to both heads but dont i need another one for the back? or do i block those ones off?

BandDirector Blk98ZM6

iTrader: (21)

The LS6 is running GREAT on the stock tune! I actually thought the motor was missing because the car can get pretty shaky at idle, but AutoTap says it's OK. I then talked to a friend that has a C5 ZO6 and he says that's a common complaint among ZO6 owners because the LS6 cam is big enough to cause a chopy idle, so it's normal...LS6 idle just isn't as smooth as the LS1, at least on the stock LS1 tune.

I do have headers, but they're Hooker shorties...I HAD Jet-Hot LT's on the stock LS1 when it tore up and I'm not 100% sure they didn't have something to do with it...when we got the headers off, it was obvious they were leaking badly...there was black soot below the gaskets on several cylinders. I never could get my LS1 to run correctly (SES light all the time, and serious problems with the O2's being moved so far back) with the LT's, so I opted for a set of shorties with the LS6 because it's looking like emission testing is coming to my area in the next few years anyway.

As far as the coolant tub is concerned, if you use an LS6 intake, then you will need to get block off plugs for the rear coolant holes to use in conjuntion with the tube for the front of the LS6. I ordered the SLP LS6 intake with EGR provisions and it came with all of the necessary tubes and block offs.

I finished my LS6 swap 2 months before my 1st child was born, so I bought an SUV for a daily driver and my Z sits in the garage most of the time and I can't seem to find the time to put the mileage on it I've had several offers to give me a hand with that though

98z28chevy

Cool thanks for help. Also did u notice any type of fuel mileage decrease ls1 vs ls6? Cant wait to get mines in i got a deal on my 04 ls6 paid 3125 drove 4hrs to pick it up. Alright i'm gonna have the get block off plugs do u know if its a GM part? ill just go to GM and order them. This is the part number i found suppose to be GM # for block off plugs 12570678. Car looks really good. Also if u know anyone with C5 vette i have stock 04 Z06 oil pan pickup tube and harmonic balancer less then 4k on them also have some sensors on the motor still will i be able to use any of them? like the Cam position sensor can i use that on my 98z or the connections are different?

BandDirector Blk98ZM6

iTrader: (21)

Actually, I get better fuel mileage with the LS6 than I did with the LS1...I think the lack of LT headers have to do with that though...

Since I had a new '04 LS6 longblock, I had a new oil pan and pulley. I advertised it on http://www.corvetteforum.com and got $350 for the pair. You might be able to get $200 or so for the pair used.

Yes, you can still use the cam position sensor, but you need to use your '98 LS1 oil pressure sending sensor, and I'm fairly confident you'll need to reuse your '98 LS1 knock sensors too. My LS6 longblock didn't come with the temp. sensor, so I had to use my old one, but I have no idea if the C5 one will work. My LS6 block also came with a new oil level sensor with the F-Body pan as well as a C5 one in the C5 pan, but if I were you, I'd just use the F-Body sensor since it's already installed in the pan. When you swap pans, you will have to use the F-Body windage tray because it's shorter to allow for the oil pickup tube to be mounted in a different location than the C5. You'll also have to use the F-Body oil pickup tube.

I can't answer the question about the GM part # for the block off plugs...mine came with my SLP LS6 intake w/EGR.

Feel free to email me if you have any problems during the swap, it's pretty staright forward, but there are always little minor glitches...

98z28chevy

alright thanks Band i found part number for block off plugs was able to order them from GM.