AsEpSiS

iTrader: (11)

I have a 98 T/A m6 135k mi with full bolt ons, fresh tranny rebuild and full suspension. I KNOW the car was run hard before I owned it. It was stock when I got it, the tranny was like mashed potatoes and I saw marks where headers were installed, red neck underhood paint, mismatch tires, ect. It had to have been heavily modded at one time. The interior and paint is great, and I got the car pretty cheap. So, over time I added the bolt ons, fresh tranny and sus parts, wheels, LCA, yada yada...... Now it comes time for the motor!


My goal is to build the car to around 450-500 rwhp. nat aspirated, no spray.
I intend on auto cross racing it once and awhile and having a mean street rod. Im affraid if I build my LS1 and run it on the track.....it'll blow soon ..lol

My question is.....Should/can I rebuild my 98 LS1 or buy a LS6? I've seen kits in summit, but I've heard the 98 block isnt able to be bored out, and a real rebuild is nearly impossible. However, 1999-02 are able to be bored and rebuilt.

I have a friend that has a 05 GTO LS6 short block with underdrive pulley with 40k on it. I can buy the it for $500. Another friend said he will complete the swap (ls1 to ls6) for $1200. He's done a few already, so I trust him (I hope).

I have a projected cost of the entire operation costing about $3,500 to $4,000. Factoring in valves, springs, heads(head work too), cam , labor ect. and selling my LS1.


Are these prices sounding about right to you guys? Can/ should I rebuild my Ls1 or buy the Ls6?

How much better is the Ls6 than Ls1. I'm learning that its more that just alil bigger cam and better heads tossed in at the factory.......

I'd just like to have some opinions!

Arc00TA

iTrader: (17)

Get the LS6 if you can snag it for a good price, 500 for the shortblock is reasonable. The block is superior in both oiling and crankcase breathing. The 98 is just the ugly duckling.

I did that swap on my 99 TA, I had an 03 LS6 that had a melling high flow oil pump and a 224 cam. I put my pacesetters on it and laid down 422/402. Stock untouched 243 heads, only other upgrade was some dual valvesprings.

omarrakeen

iTrader: (2)

LS6 for sure. just make sure its 2002+ i belive its stronger. good luck my car just hit the 125K yest

98ws6blk

98 block can be bored out...just has to be re-sleeved.

madball

iTrader: (2)

I would do the ls6. Also I would find some ported 243 heads and ls6 intake, decent cam in it and you should be at your HP goal.

Josh18Fan

iTrader: (2)

I'm guessing you mean LS2 and not LS6, given it's out of an 05 GTO?

Paul Bell

iTrader: (9)

That's what I was thinking. The LS1 has the same bore as the LS6.

I'd go for more inches.

redbird555

iTrader: (14)

U probably already know this but if your going to rebuild your motor anyway why not just use your existing block and rotating assembly? aside from the bay to bay breathing and oiling passages an ls6-ls1 shortblock is the same. While it is true a 98 block cant be bored the 99-up really isnt any better including the ls6 block. At most they can tolerate a .010 over bore whereas the 98 block will take a .005 hone. So as long as your planning a build why not save some money from the ls6 block and buy a decent set of heads or stock ls6 heads along with a cam and make better hp than an ls6. Some people will say the ls6 is stronger and while that may be true a lot of people make big numbers with 98 blocks... The only reason I would consider an ls6 block over yours would be if it had very low miles and was a steal. just my .02
Dan

redbird555

iTrader: (14)

Sorry I missed the part abt the gto engine if its from an 05 gto it is an ls2. The bigger cubes are nice and with a set of heads and cam it will make a lot more power than an ls1/6. HOWEVER to make the ls2 work you will need a knock sensor relocation harness because the knock sensors on the ls2 are in a diff location along with a crank extension harness as its also in a different place. Also the ls2 intake sucks and requires more work to work in your car than its worth so being youd need an intake anyway either use your existing ls1 intake or buy an ls6 for a few hundred (best option).
OR with the ls2 having a 4.0 bore you could run l92 rectangle port heads which require an l76 intake but in the end you would have more hp and torque dollar for dollar than you would with standard cathedral port heads. Thats another topic though let us kno what your interested in doing and perhaps we can all chime in some more...

Paul Bell

iTrader: (9)

I think you've lucked out here. The '05 LS2 engine has a 24x crank ring. Starting in '06, it went to 58x.

The LS2 should work well in your car. You may need to extend some cabling.

BTW, agreeing with redbird on the ls1 vs. ls6 block info.

redbird555

iTrader: (14)

Thanks Paul and to the reluctor ring thing every 06 ls2 I've seen has a 24x wheel on it I heard in very late 06 to 07 they changed.

disc0monkey

iTrader: (10)

go with a new/used motor built by GM unless your getting a good lsx shop to build it up.

AsEpSiS

iTrader: (11)

Thank you so much for all of your feed back!! The motor that is available for me to purchase is out of a 04 GTO....not an 05...sorry!!! However, the guy claims it is an LS6 block. He told me that in some instances a LS6 block was used in place of the LS1 in some 00-02 f bodies and also in some 04 GTOs....is this true!?!?

Thanks again!!

redbird555

iTrader: (14)

yes its true an has to be verified by casting number... its just the block so there is NO hp difference. but if your keeping the stock cubes refer to my and pauls post.