conradb

I've been trying to do some homework here, and it appears a lot of people like the LS3 motors for C5 engine swaps. I'm not sure I understand why it's so much better? The LS7 makes the kind of power I want right there with an extra 0.8L of displacement to work with.

My '02 C5Z is becoming an almost dedicated track rat now. Besides more power output, I'm mainly concerned with getting the dry sump system to go along with it, so C6 Z06 or Grand Sport donors are my goal. I'm aiming to get a running engine from an insurance auctioned C6, and part out and sell what I don't need to recoup some costs.

I know there are a couple concerns about the reluctor wheel and other sensors, but I've seen some companies selling all the proper equipment to integrate the C5 PCM with a Gen IV LS block. I also know I'll have to get a battery relocation kit since the dry sump reservoir will need to be fitted where the battery currently is.

The C6 GS has a cooled transmission setup that would be awesome to entirely swap into my car too. Can the GS transmission easily be swapped into the C5? Does the C6 Z06 have that (T56 and T6060)?

Is there anything else I'm missing? Thanks, everyone!

~Josh

I believe the Z got the 6060 in '08. It can be swapped (there's tons of info out there) but the rear tires will end up somewhere around 1 inch more rearward in the wheel wheels than current.

My vote is for the LS7 mainly because it's got gobs of torque from the 4" stroke, and with a forged crank and exotic titanium connecting rods that spins to 7krpm out of the box... With a little valve train work guys are turning them to 7500+ and they live. That's pretty stout.

Drewstein

The major reason, cost. The LS3 just costs less and can make similar power so why not. Without including cost you may as well ask why not a built ERL 442ci motor?

The LS7 is great and can run strong but you even mentioned it's more complex of an install for not much more.

wvufan1965

Ill throw the LS4 383 into consideration. Love mine An LS3 needs a superchrger to barely take me. good luck to you whichever path you choose

Nate@VanBortelChevy

I think when it comes to performance, maintenance and repairs for the $, LS3 wins. An LS3 can be had for much less $. I think a lot of people are afraid of the valve train issues of LS7 as well. If $ weren't an issue, I would go LS7, sounds more bad-*** to say I have a 427/LS7 in my C5.

sean.b

I've shopped both, and I cant justify the LS7. It's so much cheaper the do the LS3 and a dry sump setup of your own that you could literally get a pair of LS3's for the cost of most LS7's ive ever seen. And then assuming you got the LS7 anyway, you need to pull the heads off before you submit it to track duty.

If $$ were no object, then hell yes LS7. Or if you can afford it and just want it, rock on. Nobody on these forums will say thats not cool as hell.