Are the mounting points on gen3 and 4 engines the same, such as motormounts and bellhousing? What are the problems with swapping an aluminum block into a truck with an iron block? I plan to make between 450 and 550 hp with a custom TT setup.

I've got an 02 denali lq4 and am thinking of doing a custom engine build rather than modding my stock one. So I got to thinking, why not just buy an ls2 block, custom heads and cam, etc. I'd be building it from the ground up, so I could buy whatever mix/match parts would be best suited.

I understand there is some difference in cam sensor and knock sensor between these blocks? I'm unsure how this could affect my buildup.

 

you can get 450hp out of a n/a ls2 without much problem; a simple bolt on supercharger then shoud give you your 550hp. ls2 starts with 400hp; add heads and a good cam, and you should be pushing at least 450hp.

 

Hmmm, let me clarify. 450-550 WHEEL hp.

 

i heard once that the ecu had to be changed because the calibration for the knock sensors was diffrent. not sure though. i had a ls1 in my silverado and it was fine ran great. as far as i know there is no worries about drop a aluminum. some of the new trucks have aluminum blocks in them stock. it should bolt right in though. just some wiring and some some things and it should be a striaght foward swap.

 

Well, clearly I'm going to run a custom tune, probably try to run the car intake and fuel injectors, etc. I just wanted to make sure I didn't get it all bought and then find out it wouldn't bolt up, or that there's some small electronics difference that prevents it from working properly.

 

nope should...well... you have a regular cable driven throttle body right? the ls2 is dbw. and i'm not sure you can adjust for the other type of knock sensors with justa tune i think you need the ecu itself.

 

ok her is what i found. you'll need to swap the knock sensors on the side of the engine to LS1 sensors, then modify the engine harness to reach them. and make sure the new eng has a 24tooth reluctor wheel if not you will need a new ecu. the newer engines have 58tooth Easiest way to tell is the crank position sensor above the starter, if it's black, you have a 24x, if it's grey, you have a 58x. oh and you'll have to either get a after market cable driven throttle body for the ls2 intake or just find a ls6 intake and put your throttle body on it. then a good tune and your set.

 

Unfortunately I have a DBW throttlebody, which means there is apparently no easy answer to an intake swap. If I get the ls6 3 bolt intake manifold my TB will bolt to it, but even after moving all the accessory drive **** to clear the TB, I still have a 76mm TB on a 90mm (I think?) intake manifold, which kinda defeats the purpose of it all.

Then I thought, why not get the 85-90mm DBW throttlebody for a car and use that. But I am told they will not work properly on the truck, not opening fully which again defeats the purpose of the mod.

I have also read that you could get a TCS (I believe) to operate the car DBW TB with the truck ecu/wiring, but the info I've found was pretty limited and vague.

I personally wonder if there isn't a way you could swap the truck DBW electronics onto the car DBW TB so that it would open fully...after all, 90 degrees of rotation is still 90 degrees regardless of diameter of the plate. All the throttlebody is, is a chunk of metal with a shaft running through it, so why won't the truck DBW electronics swap onto the bigger car throttlebody?

I assume that even if I got a cable-style pedal, cable, and throttlebody, I'd no longer be able to use cruise control on the truck, which I wouldn't be happy with.

As for the engine build/setup, let me start over, it may give you better insight into my line of thinking.

First I thought, I will just do the TT setup on the stock engine and only do necessary fuel and tuning mods.

Then I realize that when I try to unbolt my stock exhaust manifolds for the turbo install, I am quite likely to break off several, if not all, the stock header bolts (a PO has already broken off one, and they are all rusty and will not turn). This will, in all likelihood, result in the need to pull the heads. Which will mean I will have the intake all apart as well.

So I think to myself, hell, thatd be a good time to do a cam and valvespring swap, and maybe use a car intake instead. I mean, I have to buy fuel injectors anyway, and car injectors are just as easy (or easier) to get than truck injectors.

But then I remember that the rod bolts on these engines are said to be weak at the power level I want to make, but changing them as preventative mods means dropping the oilpan, which is a bitch on my AWD truck. So then I think to myself, screw it, I should pull the whole existing engine (runs perfectly at 80k) and sit it in the corner "in case **** happens" and just build a whole new setup instead of trying to mix and match stuff onto this one. It'd also give me the opportunity to drop in the rebuilt trans and stall that I'm told I'll need with such a setup as well.

So I thought, I might rebuild an ls2 6.0 aluminum block, with rods and bolts, custom turbo cam, valve springs, rods/bolts, pistons, perhaps even lower compression ratio slightly to 9.0 or so (using whatever head/piston combination would be suitable), and run a car style ls6 intake. BUt I still dont know how to handle the throttlebody issues.

Nor do I know where to start looking for a vendor that can put together a total package for me without charging 10 grand or selling me a bunch of **** that won't work well together.

 

ok the ls6 intake is not a 90 mm intake. its a perfect fit to your stock tb. the internal tb parts intake swap thing has been tried it don't work. its kinda complicated. but there is a guy working on making us a 90mm tb that will work for use. so hopefully it will come sometime soon. there is a thread on it just do a search. but the ls6 intake is good to make alot of power. alot of ls1 guys do it all the time. i think most of the 90mm guys on here use them for the supercharger j tubes and for the edelbrock intakes.

the ls2 will bolt right in no problem everything will bolt right to it. you just have to put your knock sensors in place of the ls2 sensors and add wire to reach. and make sure you get a 24 tooth reluctor ring on the crank. and the cam sensor. some people say go for iron for turbo though. you could save alot of money by useing your eng you has being that it is already a 6.0. the compression is higher in the ls2 also. so you have to figure out a way to lower it. being pistons or headgaskets or what ever.