in the end the ls6 block and ls1 block are virtually the same, there is no proven hp gains from haveing the ls6 block just better crank ventilation. I am tellin ya'll just do the heads, cam , intake swap and you will be better off then fabbin parts, and makeing sure crap lines up. All you have to worry about is a good tune.

 

There is no "fabbin parts" for the ls6 longblock swap. It's a direct bolt in with ONE minor exception. The LS6 got the updated PCV system, so I had to buy about a foot of 5/16" hose to reroute the stock PCV from my '98 to the LS6. ALL of my accessories bolt directly to the LS6 longblock. The longblock also comes with the F-Body Oil pan in the crate, so swapping of the oil pans is necessary, but GM includes all the parts AND I can now sell the Corvette oil pan to recoupe some of my money.

I agree that if you have a low mile ls1, and you desire an ls6, doing the ls6 heads/cam swap for 1/2 the price is the way to go, or even going with another set of ported heads and aftermarket cam will get you even more HP than the ls6. However, if you have a higher mile ls1 and you feel a rebuild might be in order before a heads/cam swap, then you need to consider the LS6 longblock. An ls1 rebuild will run around $3000 if you put everything back to stock specs. If you want more HP, then heads/cam on the rebuilt block will run another $2500, so you're now at $5500.

A NEW LS6 longblock is $5230 SHIPPED...there is NO core charge, and with used ls1's w/75K miles or so going for $1500 AND you can sell the Corvette oil pan for probably $200, when it's all said and done, you can have a NEW LS6 with 405 HP for $3530 WITH a 12 month/12K mile warranty. If you just buy LS6 heads and cam, you're looking at roughly $2500 in parts, but if you add them to your ls1, then after it's all said and done, I've got a new shortblock for and additional $1000! If I could have had a "built" motor with warranty for that little, I would have gone with it, but that kind of deal was no where to be found. If max HP and no warranty is important to you, and price is no option, then do a heads/cam swap and have the existing ls1 rebuilt with 475-500 HP, but if you want the max "bang for the buck", then I think the LS6 longblock is the best option over a rebuilt motor with heads/cam.

 

yes you can get the LS6 block for 5 large, but that doesnt include price of install...when said and done a rebuilt LS1 with LS6 heads cam intake will prob be far cheaper then a new LS6, plus install. Besides most shops warranty there rebuilds for a certain ammount of miles, prob the same as the LS6 fact warranty.
Also a shop is going to charge you out the **** for the LS6 swap since they have to do all the guess work. I am not nearly experienced enough with these motors to try to swap them in, hell just takeing off the valve cover scares me. If it was a SBC then i would say yeah swap it yourself, but for those not as advanced on these motors and most shops arent, you are going to have to go to a speed shop or a speciality shop to have it done is going to cost you. I wouldnt mind droppin in an LS6 but for the cost its gunna be more then a rebuld with not much more to offer.

 

Actually, it's cheaper to do a motor swap than a heads/cam swap. I'm having the motor swapped for $600. The same shop wanted a $1000 for a heads/cam swap because there's more work involved. Of course they actually prefer to drop the motor for the heads/cam swap to make sure they torque the heads down properly, but I realize it can be done cheaper if you leave the motor in the car for a heads/cam swap. However, there aren't too many shops in my area that have internal ls1/ls6 experience, so I felt better about having a motor installed that was bolted together by GM than risking someone locally who may not have the necessary experience to rebuild the ls1...of course there were several shops willing to "give it a try." Of the reputable shops that I found, if I planned to get more HP than stock out of my ls1, then their warranty went out the window.

You also bring up an interesting point when you say "Also a shop is going to charge you out the **** for the LS6 swap since they have to do all the guess work." I personally wouldn't want that same shop doing a heads/cam swap on my motor. The ls1/ls6 motors are still new enough that a lot of local shops still don't have the necessary experience to work on our motors internally.

When it comes down to it, anyone thinking of doing a rebuild with heads/cam or going with an ls6 longblock needs to research both options in their area. Of course I found the best deal at a speedshop north of Chicago, but by the time I paid for the transporter to get my Z up there, it was no longer the best route.

IMO, people can argue about which is the best route all day long...it's until you actaully look at ALL of the cost involved and get ACTUAL quotes for the desired work that it starts to become clear which is the best choice for each individual person.