*** Warning, this is a long read ***

For the past 3-4 months, I have been on LS1tech nearly every single night just reading everything I can find on various topics. My head is literally spinning. I feel as if i've found a LOT of the answers i've been looking for, but i'm still not clear. I'm basically looking for some answers or at least point me in the direction where I can find my own answers.

Here's the skinny. I've owned a 2004 Mustang since new until now. I have gone through many, many setups and the most previous build was the most extensive. The last setup layed down 598 rwhp/ 650 rwtq @ 15 lbs only spinning to 6,000 rpm. Due to a bad tune and apparently a motor that wasn't what it was supposed to be, I lost a ringland off the #8 piston. This was with a 4.6 modular 2valve motor that was "supposed" to be built well beyond what I needed. I payed to have CP pistons, the rotating assembly balanced, block bored .020 over, fly-cuts put into the pistons, and assembled, etc. After the motor blew up, I spent a few months looking for good deals on pistons and landed on a set of Diamonds for a steal. Tear down the motor to inspect the cylinders and pull out the rotating assembly to find that the block is stock bore, I have Mahle pistons, and the "fly-cuts" were done with what look like a grinding wheel on a dremel that aren't anywhere near the same piston to piston and look terrible. Guess where the ringland came off the piston, yep right where the "fly-cuts" are.

Needless to say, after spending over $8,500 on a built modular motor and another $1,000 to have it tuned by a local guy that has a great reputation and getting screwed by both, i'm done with the modular/efi nonsense. After extensive research, I have decided to go LS/carb. Now at least if a motor blows again, I can blame myself instead of paying someone $1,000 to blow it up for me.

My mechanic (diehard Chevy guy) found me a 6.0 iron motor. I believe it's an LQ9, but I haven't looked at the pistons yet. The motor has rod knock, but he picked it up with accessories for $200 so I couldn't pass it up. Now here is my dilemma: Do I rebuild this motor to run n/a and spray it or do I find a good shortblock, leave it stock and put my turbo on it.



Option 1: N/A + Spray. The only way I would do this is if I can achieve 500 rwhp on motor. I'll spray a small shot (150-200) to run the times I want to. Budget: $6,500

I would use my existing rod knocking 6.0 and rebuild it using a set of h-beams and diamond pistons on the stock crank. I may bore the motor, I may not. Depends on what the cylinder walls look like (the motor has under 100,000 miles on it). I currently have the 317 heads on it, but i'd like to swap them for the L92 heads and work them very little.

-If i've read correctly, the L92 head swap is a straight bolt on to the LQ9 motor because of the 4.000 bore size. Is this correct?

-With doing the L92 heads, longtubes, GMPP intake, some sort of decently large cam, valve springs, rotating assembly, and a carb probably from Pro-Systems, would I net 500 rwhp (for conversation sake, through a T56)?

-What is a safe number to spray on the stock crank and forged internals? I have more fuel system than I know what to do with so don't worry about that. It consists of a sumped tank, Aeromotive Eliminator pump, -10 feed, -8 return.


Option 2: Turbo. Budget: $3,000

To do this I would use another 6.0 shortblock that's sound without damage. I would replace the rod bolts with either the Katech pieces or ARP along with the valve springs to control valve float. I would keep the 317 heads and possibly add an LS6 cam. A blow-thru carb from Pro-Systems would be used and I would keep the boost down so that i'm not netting more than 600 rwhp because of the stock internals. My existing turbo kit would need to be modded to fit the manifold location of the LS motor and I would have to modify the cold side slightly to meet the top of the carb.

-I could always start to slowly scavenge parts to start building a forged motor, but it would be a very slow process.

-I need the motor to last at least a year or two.


Now, what would YOU do and why? Consider the budgets that i've listed. I have already taken into account the money needed to be spent for gauges, new fuel pressure regulator, etc. just to make the swap work in my car. Thank you in advance for ANY help or advice on the topic.

 

Sorry to hear you got "hosed"...that sucks. You would be doing everyone a favor if you posted the shops/persons name that did such shitty work.

For a cam I would highly recommend a custom from Pat G or Predator Z...Pat G was my choice.

Hopefully these link will be of some value...
https://ls1tech.com/forums/generatio...s6-recipe.html
https://ls1tech.com/forums/generatio...heads-cam.html
https://ls1tech.com/forums/generatio...t-stroker.html

You are right about it being a "long read" which may steer some guys away from spending the time to get all the details.

 

Honestly, there are for whatever reason, retarded good deals on low compression 6 liter pistons, so that is kind of a head start, you can get the nasty I beams from Scat for about 300ish and the stock crank will be fine, boost it to 16 PSI and point/hang on.

If you are ready for all the work yourself, have at it, im sure it would be cheaper than any mod motor and make more power with a extra 1.4 liters.

 

The shop that built my motor is now closed, but only did modular motors and Mustang specific stuff. The tuner is now not tuning cars anymore and mainly focuses on building higher end cars like Atoms and Gallardos along with the occasional Supra.

Thank you for the threads. I've seen two of them, but not the 6.0 one for some reason.

I don't think I can afford to build the motor and run the turbo. After getting the parts, the machine work, and then the balancing, i'm looking at over $2,000 just in the bottom end which is already pushing my budget.