I have a new to me 94 Z28. This is a pretty nasty build.
LT4 intake
LT4 Hot cam W/1.6 rockers
Cam= 218/228 duration@ .50", .525 lift , 112 centerline
Airflow research LT4 heads
.20 over pistons 11:1 compression
Forged Eagle H-Beam rods
SLP light weight flywheel
Centerfource Dual Friction clutch
SLP light weight flywheel
12 Bolt 4:10 Posi rear end
Spohn Performance Torque arm with relocation brace and drive shaft loop.
All Spohn rear suspension
Completion Engineering drag shocks.

This is basically a street bruiser drag car.

I was able to get her out and about some and finally and drove her to work today. Trying to learn the car and what is a normal noise and what is not.
She runs great, shifts, smooth (I'm still getting used to the clutch, so sometimes NOT smooth) handles OK, its setup for drag racing, not corner cutting. (that's gonna change), brakes are good and over all feels good.

However, not being used to a build like this, not sure what is a normal noise and what is not. I have had all automatics for Camaro's and my manual trans have been little imports and trucks.

This car was supposedly built by a very good speed shop in Detroit, but without papers - it's all hearsay. Mike's Machine Shop Wixom MI did the engine work. All of the suspension and rear end appears professionally done and done right and not half assed.

Not being used to a T-56 and this setup, not sure what is a normal noise and what is not.
So I have a bit of a howl/whine in 4th at 40-50, which goes away on acceleration or deceleration. Shift and 5th is not too bad, still a slight howl/whine but not bad, and 6th again a bit of a howl.
Its at the cruise point, when you're not accelerating or decelerating.
Now with the rigid rear suspension build, relocated traction bar, trans cross member and hardware, I don't know if this is normal because nothing is really dampened for noise. For all I know this is to be expected because it all radiates the noises, or this is normal because of the 12 bolt spool and 4:10 gears.

The noise seems to be coming from mid car. I do NOT feel it in the shifter. It does NOT change cornering or braking.

I have not checked fluids, that was suggested to me. I read some posts about where to check that on the T-56. GM diffs are all the same. The car was at a consignment seller, there was no indication of fluid leaks from either trans or diff.
Does the car have to be level to check the T-56? Or can front be jacked up enough for me to slide under and pull the plug and check it?

So what I'm asking - could this be normal? Or should I start looking deeper? Anyone with a similar build?

Thanks gang!

Pic for attention!

 

You should hear my C5! I figured out that it needed a bit of sound deadening in the console area. The noise is a distant memory now. As an aside, your rear end may not be set up correctly resulting in that howling. I doubt if it's that. I would bet it's ok and you need not worry about it. Get some sound deadener in there!

I owned a 96 Z/28 new in 96. 6 speed car. It eventually had more work than yours ultimately resulting in a 538 being installed and going racing. You didn't need to worry about any noises as the car was pretty noisy w/ open exhaust.

 

HA!!! I want to change the muffler & tails as they reused the OE muffler and tails for this build.

Sounds good, but really reduces the sound of the cam chop, that I want to hear.
I'm thinking Hooker Super Comp exhaust. I heard one on a stock LT1 car and it sounded awesome. Its also not hugely expensive.

Thanks for the feedback!

 

I poured a ton of money into that car. 383, Moser rear, suspension, you name it, I did it. Now I have a C5 that is just like the Z. The trans is the same and the car drives just like the Camaro. In other words, really great. Please post back when you get the sound figured out. 538 BBC, Turbo 400, 4.11s. Low 9s.