Originally Posted by 440_Stroker

I have a Gen IV block with the 24x crank. It's a 4" stroke and the 5.3 block was sleeved and bored to 4.185. not exactly what you're after but there are options. A custom built engine is NOT cheap but it's doable.

Originally Posted by 1BadElky

So, stupid question alert : Can I just get my LS1 bored/sleeved to 4.125 and get a 4.00 inch crank and build a "Gen 3 LS7", or is that a bad, expensive idea?

Originally Posted by 1BadElky

So I can get a brand new 6.2 for a decent price - but I hate to immediately tear it down to remove the crank and change reluctors, so is it possible to pull the crank without removing the heads and pistons? ie just pull the pan. mains, caps and spin it to push all the pistons to TDC and then lift out?

Originally Posted by Darth_V8r

If I were in your shoes and bought a brand new 6.2L for the swap, I would not want to void the warranty to put a 24x on it. The lingenfelter box works great as long as you keep it out of line of site to the headers. heat is what made the thing have a reputation for unreliability.

Originally Posted by black00TA

I want to throw my .02 in here...try to find a low mileage takeout 6.2 and save yourself a ton of cash, and anything you can do to avoid opening the engine up is recommended. Keep it simple and you will have a more pleasant experience.

The 6.2 platform is a superb value.

Most guys who own LS7's won't recommend swapping them into cars because of their cost, and parts not being interchangeable.

Originally Posted by speedfreak440

I did all of this about 4 months ago, I wouldn't call it easy as there are a few things to tackle along the way but I can give you a rough rundown on prices and what to expect... I had an 01 Trans Am LS1 6speed and went to an L92 6speed, alot of this Darth and others have covered but I was looking for something in the 475-500rwhp range with good manners that I could beat on at the local road course (Barber) and not break the bank, I ended up with 485rwhp/461rwtq with a somewhat mismatched cam, I am VERY happy with the performance, here is what I did.
$3800 found a local L92 that already had new F-body pan, ARP head studs, untouched ports just light resurface on the deck, already had FULL VVT delete, trays/trunions, BTR .660 springs & "Non-High volume" oil pump (If you get a VVT motor make sure and do this if it hasn't already been done). bottom end was untouched with a claimed 75,000ish miles, I tore it down/inspected everything just to make sure it was as billed, everything checked out so I just reassembled. This motor cam with a new just installed 3 bolt BTR Turbo stage II cam 226/231 .605/.598 113+4, while not technically a NA cam it was pretty close to what I was looking for in a cam even though I have zero intentions to go turbo, it runs hard, made great numbers and has good manners, long sorry but trying to give you the full story....

$1200 FAST LSXR 102 LS3 style + Nick Williams Cable throttle body
$1000 Injectors + All the other stuff you don't think about when going this route Fuel rails, lines, I got a fuel guage for quick ref under hood, I got all FAST stuff which I am mostly happy about the only one I'm not is the quick coupler to hook up to the factory hard fuel line, mine would not go on no matter what (others have had this problem as well) I ended up getting another one that I will link to. - SIDENOTE, even though the FAST 102 ended up costing more than I had hoped to spend I'm still happy I went that route I am SD tuned and having a nice clean 4" funnel going straight to the throttle body is great and had to be worth some power.
$225 Lingenfelter 58-24 box, My L92 had a 58x relucter wheel and I didn't want to mess with changing it so I went this route not in small part because I saw Darth running it with no issues at 9,000 RPM or whatever he's shooting for these days Your my hero dude.... anyway I figured that would work great for my little 6500 rpm motor, no issues so far, it's a really well made product, I just wish a couple of the wires had been longer.
$500-infinity and beyond MISC, this can really go as far as you want but you will NEED injector adapters, cam signal adapter, I moved my MAP sensor to front location on the FAST so I needed an extension for that, I drilled out the sides of the block and did the LS1 style knock sensors + the conversion harness for that, none of it costs all that much but it adds up quick, I also did new LT1 radiator, clutch, pilot bearing, water pump/thermostat, starter + heater hose lines while I had everything out just because the car is 20 years old, I also did a UMI road race Kmember. the list goes on.

All in all I spent right around $7,000 but I did some extra stuff too and I'd do it all again in a heartbeat, you could do it a little cheaper but not much. It's a lot of work but it's probably not as bad as it sounds the little things add up though, I spent a whole day going around the motor while it was on the k member just tidying up wires, running them exactly where I wanted them to keep them off headers/away from sharp edges etc.

Originally Posted by 1BadElky

Follow up question speedfreak - how is your MPG? have you checked?

Originally Posted by black00TA

Most guys who own LS7's won't recommend swapping them into cars because of their cost, and parts not being interchangeable.

Originally Posted by indyjps

If I were in your spot, Id really consider building a replacement engine - and making the move to square port heads.
Takeout 6.2 is a premium price vs 6.0 that needs built, and youll have a lot of conversion cost to run 6.2 as is.
Build will let you stroke it with 24x or at least change it.
Intake and DBW or cable throttle body is a toss up, conversion to DBW cost VS larger cable throttle body.
Interested in what you come up with

Originally Posted by QwkTrip

I have a H/C/I LS7 and it did get pretty expensive. I would never do it again. Boost is cheaper.
The LS7 is a bad little **** though. It will not disappoint in the performance department.

Originally Posted by 1BadElky

I'm going with the 6.2 and the corresponding square port heads. Sticking with a 90mm cable TB on L76 intake. 6.0L is a firm no for me because it just feels icky putting an iron block in a car that had aluminum from the factory (boosted might be a different story, but that's not my plan). I'm just waiting on a local engine builder to get back to me on whether I need to provide the 6.2 core or if he has one available.

Originally Posted by black00TA

Why having an engine built?

Originally Posted by 1BadElky

Getting estimates for both - basic machine work on the short block (with me completing the build) vs getting the full long block assembled and having a warranty

Originally Posted by black00TA

I guess my question was, why do you feel this is necessary? How does that actually suit your needs VS a low mileage stock takeout?

Originally Posted by 1BadElky

I see - it basically comes down to a matter of cheap insurance. Since the swap to a gen IV will require that I at least partially tear down the engine to change the reluctor, timing set, cam (upgrade), lifters, guides, oil pump, windage tray, etc...

I suppose once it is stripped to the short block I could look at the cam bearings and cylinders and assess from there whether a rebuild is warranted, but I prefer having the peace of mind knowing its a "like new" engine since I dont really want to have issues in 6 months and have to drop the K-member again.