shadowfirep

I have a red 99 Z28 that I've put a lot of work into. I know I won't ever get back the money I've put into it, but I'm at a point where I might consider selling if the car is worth enough to someone. How can I figure out what it is worth when it is so far from stock? What do you guys think it is worth? I'm at work right now so i have no pics, but i'll post a couple when i get home

standard LS1 block bored to 3.903
SCAT rotating assembly (4340 forged)
-4.000" stroke crank
-6.125" I Beam rods
CP Carrillo bullet series flat top pistons with 3cc valve reliefs
-supposed to be 11.5:1 SCR (actually closer to 11.1:1)
TFS 215 heads
-Harland Sharp SLS17 rockers
-Cheverolet Performance LS1/LS6 head gaskets
-P/N #12498544
TFS-21407500 Chromoly pushrods
TFS-30602003 Cam
-283/286 .585/.585 112
CompCams hydraulic roller lifters
FAST LSxR 102 Intake
FAST Big Mouth 102mm TB
FAST Precision flow LS2 style 46lb/hr injectors
FAST billet aluminum fuel rails
100mm MAF from Texas Speed
104mm air box lid (can't remember brand, maybe SLP)
Fast Toys Ram Air System
PHAT full exhaust (can't find company anymore)
-1 7/8" L/T headers and 3" all the way back
Melling oil pump
-started with a high volume, but the engine blew up once and idk if the shop changed to high pressure or not. I just know they stayed with melling (if they replaced it at all)
Upgraded fuel pump (can't remember specs or details)
Strange S60 rear end with 3.73:1 ratio
Pro 5.0 shifter with Lou's Short Stick (super short shift stroke)
Monster Stage III clutch
Upgraded brake rotors (slotted and drilled)
upgraded brake pads
Red/Black Corbeau racing seats with submarine hole (driver and pass)
Slightly upgraded stereo system
-new deck (moderate quality)
-pioneer speakers
-dedicated amp to run speakers (they sound better that way)
SLP 3 point square tube weld in subframe connectors
Brand new (less than 500 miles) Nitto NT01 tires
-315/30/R18 rear // 245/40/R18 front
Brand new (less than 500 miles) OE corvette wheels
-18x9 front // 18x12 rear

As far as negatives go, the fourth gear sychro does not work so to shift into fourth gear the RPMs have to be right otherwise it grinds (not sure why that happened, maybe bad blocker ring from thegearbox?). Also, it needs a coat of paint as the black top is faded and has small cracks.

shadowfirep

So I may have found something close to a value? I took all of the mods listed above and found what the parts cost new today. I then inputted their current age in miles. I figured out a decent life expectancy on those parts and depreciated them based on age/life expectancy in miles. This depreciation should give me what that part is worth (roughly) as it sits in the car. I then added up all of the depreciated costs and added that total to the average of the blue book value with the NADA value. This gives me just about 23K. Does this method sound legitimate to anyone?

(mileage for kbb and nada values was the average mileage of the odometer with the actual mileage of the new drivetrain)(odo at 155k and drivetrain at 10k for avg of 82,500 miles)

Firebrian

$23K doesn't work at all. And those averages may not have any use either. A stock 1999 Z28 M6 with 155K miles is maybe in the $5K-$6K range. And that may be kind. When figuring most mods I'd take 20-30% of their new value, and nothing for labor. Some mods might be worth closer to 40-65% if brand new and can easily be removed. I don't see it being worth more than $10K-$12K even if the trans was trouble free. You would know better than most what all those parts are worth used. You can go out and buy a bone stock '99 Z28 with say 30K miles for $10K-$12K. The world's best red/black 1999 Z28 M6 with under 100 miles isn't probably even worth $23K.

With all that work to the engine I don't see any upgrades/overhaul to the transmission. Next thing I'd do is resolve the 4th gear shift issue as any buyer is going to focus on that. It's one thing to have 10K miles on some of the drive train. But was everything from front to back redone? (ie radiator, AC, water pump, power steering, suspension, axles, transmission, etc). New paint is another issue. 155K miles on the electronics/electrical systems. The engine having grenaded once already under the new build(?) is not a good selling point.

shadowfirep

I'm going to resolve the 4th gear issue the next time I'm underneath it. As for everything else, yes the cooling system was redone, AC is stock but newly charged and working the way it should, the rear axle i put on the list didn't I (i can't see the original post from this screen) and I know I forgot to put the transmission overhaul on there. I rebuilt it with a stage 2 kit from thegearbox.org and I think the 4th gear blocker ring didn't have the right inside diameter. no way to know until i tear into it. The engine blowing up was because the instructions for the head/cam kit i got were incorrect for propely setting valve lash. This caused a rocker arm to get loose and cause loud noise before the engine was shut off. no damage to the engine, just took a rebuild to find the cause.

Firebrian

It's good that you did rebuild the Trans and are going back into to find the trouble spot. With everything working right the $10K to $15K range should cover it. You are competing against 1-2 owner bone stock, low mileage vehicles worth $10K-$13K. If as a prospective buyer you told me the rebuilt engine and trans both had issues on/after assembly that would concern me as to what might happen if I'm the next owner.

shadowfirep

I could see that, but as a perspective buyer, i would also understand the explanation for the problems. One being a manufacturer error (rocker arms) and one also possible manufacturer error (although could be my fault just don't know yet) Out of curiosity, why are you comparing my car to bone stock? I don't see how that helps because I would be selling based on the drivetrain, not so much the car itself.

Thanks for the help

Firebrian

Bone stock is the baseline, where values can be consistently determined with decent accuracy. And most potential buyers don't want to pay a lot for modifications. You'd be surprised at how often a modified car with mid to higher miles brings no more than a lower mileage bone stock version. There's less to wonder about with an unmodified car. I start all my comparisons to bone stock lower mileage cars. One way to think of it is to have your pick of a bone stock version with X miles vs. your car with 155K miles (10K on mods). I can guarantee you that for most people they'd take the bone stock version with low enough miles.

For instance would I take your car or a bone stock one with 100K miles? Your car? Same question but with 75K miles? Probably your car. How about 15K miles bone stock? At that point I'd probably take the stock version. And its value we can readily determined. There are lots of cars that can be compared. You can find a 2002 Z06 Vette 405 hp with 20K-30K miles for $23K or less. I know which one I'd take for my $23K.

If removed from your car, what is that drive train worth to you? What can you get for it? How much more (or less) is that worth than say a 15K original mile drive train? Not saying I'm right. Just offering up some methodologies. We all value cars somewhat differently.

GimmeLSx

iTrader: (4)

There is a big difference between what the car is "worth" and what someone will be willing to pay for it. You certainly have a long list of modifications with lots of expensive parts, but there is zero chance you will get $23k for it and I seriously doubt you will see $15k, even if it had no issues.

The only way to know what it will bring is to put it up for sale and see what happens. If you aren't getting any bites, then you will know that your price is too high and you can proceed accordingly. If you are wanting to maximize the amount of money you get back out of it, I would part it out. The market is very good for good quality used parts.