Hi everyone, I have a 2005 GTO with twin Precision HP6265 turbos (.68 AR), and I would like to gather a parts list this ASAP to purchase everything this weekend.

I've owned the car since January 2006 and still only have 26k miles on it. The car is really dear to me, but it is time to sell it to focus on other priorities. I want to put it back together with a fully-forged rotating assembly, with 317 heads, LS9 head gaskets, and I would like to keep the compression ratio to around 9.5:1 to 10.0:1. The car previously made 639 RWHP @ 8 PSI on 93 octane, using a Dynapack years back, and I'd like to build something capable of 1100-1200+ crank horsepower, but still keeping the budget tight since I'm only building the engine to sell the car. The car is in pristine condition and everything on the car has been done extremely tastefully, so trying to put an engine together to advertise the car as making 650-700 RWHP on 93 octane (which no doubt it will do again.. I'll just have to tune it again to get the exact numbers), and just simply needing a bigger fuel system to crank up the power (rest of the car is built to handle to bigger power). So now that you know where I'm trying to go with this build, here is what I was considering:

-New GM 6.0 LY6 iron block (Part# 12609999)
-New 4.000" forged pistons and rings
-New 3.622" forged crank w/24x reluctor
-New 6.125" forged rods w/ARP 2000 bolts

I suppose I should be able to just pop 4.000" piston right into the new block without any machine work whatsoever, since the cylinders on the block come finished? Or do I really need to look at buying over-sized pistons and having the new block bored and honed locally to match?

Is there a specific, budget-friendly 4.000" piston anyone recommends for boost? As far as crank and rods, I'm open to brands like Callies, K1, Lunati, etc.... as long as the parts are reliable and have a good reputation, I'm happy. I just don't want a potential buyer of the car to be turned off by some lower quality internals.

I would like to keep the price of the rotating assembly, including main and rod bearings, to around $2,500 or less, but if I have to go a tad over for a better product then I might be fine with that. I don't suppose I should consider a 4.000" stroke on this setup, based on my turbos, correct?

I'd greatly appreciate anyone that doesn't mind taking a few minutes to school me on this, and anyone that can point me in the right direction of where to get what I need for a good deal. Thanks everyone!

-Andrew

 

Here you go, this is my list for my 1200 horse at crank set up. With 2# 6266's.
The block is a Summit 5.3(3.780) $299.


Wiseco 3.800' Bore, 1.300' Compression Height, 3.622' Stroke,
6.125' Rod custom 1.0,1.2 2.8 XX ring package for boosted
Callies Comp Star 6.125' rods, 2.100' big end, .927' pin end, 618
grams
LJMS Stage II twin turbo cam 226/235 .605'/.610' 114+5
SK001 .660' Lift Platinum Dual Spring Kit for LS engines including
matching titanium retainers, locators, locks and seals. 155 lbs @
1.780' 380 lbs @ 1.180' 400 lbs @ 1.130' coil bind @ 1.070'
Chromoly One Piece Pushrods 7.400' Long, 5/16' Diameter, .080'
Wall, Set of 16
Discount for Titanium retainer Spring kit
LS1,2,3,6 etc. Main Studs
ARP Head Studs for LS Engines 2003 and older, unequal length
K1 LS1 346 Crank 3.622 Stroke with 24X Reluctor wheel

 

But its over your $2500 by a grand or so. And add a grand for engine work and assembly.

Personally it sounds like your done. So I would sell the turbo kit, buy a stock low mile ls6 and sell it like that.