I have a ls6 with forged bottom end, good rods, diamond pistons. problem is the car has a light knock. oil looks good, good oil pressure. sounds like piston slap, or a rod bearing beginning to go away. makes noise under load between 1000-1800 rpm and then gets quiet under crooze.

car only has about 25000 miles on the engine, but I bought it "built" so I don't really know too much about the quality of the work. It runs REALLY well and puts down 800 at the tires on alchy. but I dial it at 12 psi and run 600 at the tire on pump gas. no bad noises at higher rpms so I'm hoping it's not a rod bearing.

might be a noisey lifter or rocker, bad valve guide. the local shop wants to pull then engine and charge a TON to tell me what's wrong.

I'm not really sure whats wrong at this point or where to take the car. I'm in Alex VA. car is a Z06 Twin Turbo TTIx and really tough to work on due to all the plumbing. I replaced the pass side manifold last summer and decided I'm not going to tear into again!

looking for advice on:

rebuild it or replace it?
which would be the best shop (considering Fran in Deleware, ECS, others???)

how much should I expect to pay to freshen up the motor (ball park, considering replacing pistons, rings, bearings, gaskets, ect....)

would it be more economical to just swap in a new short block (maybe AES or some other)

not really looking for more power, car is plenty fast. I'm continuing to drive it for now and not noticing the problem getting any worse.

thanks for any help on how to trouble shoot this and which direction to go in.

I do "light mechanical" work but I'm certainly not equipped to do an engine swap or rebuild on the vette. it's a bit beyond my talents and patience.