phluxx

Sorry I’m sure it’s been asked a million times, I use to know years back but have filtered it from my brain since.


Looking to reach somewhere in the 900-1000rwhp have twin 67mm turbos those should do the trick.


so just looking for best starting platform cranks should be good till that power but not more ?

I seem to remember internals are weaker in gen 3 over gen 4?

Earlier blocks are DBW? should matter though going terminator x and buying an intake manifold/throttle body so I can change ?

relictor wheels 24x not 58x? Any significance here?


thanks for taking the time to read this I will be buying my dad a block for Christmas

AwesomeAuto

Anything 05+, whether its a gen 3 engine or gen 4 engine will work for big boost, as they all had gen 4 rods.
If its a true Gen 4 6.0, and its not an LS2, it will have rectangle port heads and an LS3 intake can be had fairly cheap.
The rectangle port truck intake makes the same power, just doesn't fit under most hoods.
All engines 05+ will have DBW, save SOME commercial vehicles (Savanas).
If its a gen 4 engine, you might have to deal with deleting AFM/VVT.

phluxx

thank you for the reply awesome!


when you say true 6.0 and not an LS2 with rectangle ports, I thought anything 6.0 and up was rectangle port and cathedral was 4.8/5.3 and true LS2 is aluminum block

I should have probably specified I’m wanting to build an iron block for boost in a somewhat economical way

i just have a shot at an LQ4 for $500 but I’m thinking it’s not a very desirable starting platform


I appreciate your replies! Cheers 🍻

G Atsma

Rectangular ports did not exist in the Gen III engine lineup.

AwesomeAuto

I said 'True Gen 4', meaning a real Gen 4 6.0 and not just an 05+ Gen 3 6.0.
The only gen 4 6.0 to have cathedral ports was the LS2. All others were rectangle ports.

If you're buying just a block, then it really doesn't matter. A gen 3 would work just fine.
If you're looking for a complete engine, typically 05-07 Gen 3 stuff is most desired.

RB04Av

"Block" is not DBW or DBC. Throttle body (and the choice of intake they bolt to) determine that.

The LQ4 "block" is the same as the LQ9; no difference.

Internals, particularly rods, may be different. Probably are in fact. Cranks AFAIK are the same. Later motors, maybe 2005 up or so, all got the better rods. It's only an issue with the older ones.

Might be worth being more specific about what you're looking for. A "block" (which is basically just a casting), short block (block plus crank rods & pistons), long block (same as a short one except w/ heads), complete engine; whether the intent is to run it as-is, rebuild it, piece it together; your tolerance and ability for adapting the wiring; and so forth. Your target is quite vague.

Rect ports started in some particular year on certain motors (LS3 & L92). They only went on the motors with larger bores. Before whatever year they were introduced, ALL LS motors had cathedral ports. AFAIK that included the LS2, LS6, LS7, etc. After they were introduced the smaller motors such as the 5.3 versions that were available concurrently, still got cathedral ports. You can put rect port heads on any of the earlier motors if you want; just don't expect them to work very well on a smaller motor (less than 6.0). The larger the displacement, the more favorable toward the rect ports.

Boost, by way of increasing the density of the material in the intake tract, makes port design and whatnot less relevant, up to a point. Max power potential of course is greater with larger ports, but if you're not going for broke that way, i.e. if something else besides the port is the limit to your power output or RPM, then the port type doesn't matter as much.

58x reluctors started in 2008 or thereabouts. All were 24x before that. The reluctor itself can be changed if you find a crank that has the one but needs to go into a complete engine setup that requires the other. ECMs, more specifically the OS, need the one or the other; an ECM for a 58x reluctor signal also wants the 4-pulse cam signal. Earlier motors had the cam sensor at the back of the motor pointed at a feature on the cam itself; later 24x motors had a sort of "half moon" looking feature on the cam gear, and the sensor in the timing cover. There are various aftermarket boxes that allow for a certain level of swappage but as far as just putting together stock stuff that's the general rule.

AwesomeAuto

The rectangle heads started in 2006 with the L76 (6.0).
The LS7 never have cathedral or rectangles, they have their own unique intake port (somewhat more square than the rectangle ports).
Rectangle ports won't physically work on an engine with less than a 4.0" bore or the valves may contact the cylinders.
Mast makes small bore rectangle ports with smaller valves specifically for smaller engines.

58x started in 2006 in nearly all gen 4 engines. Some of them took another year or two. Gen 4 engines in 2005 were 24x.

dawgs74

I picked up my lq4 in short block form for $500 too....since it was just a short block I decided to build it up and had it bored .030 over to "370 with ls2 flattop pistons and gen4 rod's with 64cc ls3 heads.....only thing that stayed original to the block was the 24x crankshaft, everything else was newly gen 4 replaced....and I live on the edge so you know it didn't get balanced....been running great now for just about 4 yrs with no issues whatsoever at 50-70psi oil pressure at any given moment