I have an 84 z28 with a L69 5.0 H.O. with 63,000 original miles. Bought it in 1998 with 60,000 miles, had that problem back then. Yes the car has sat a lot but only in a garage. I guess it needs valve seals since it blows a little smoke upon start up. It runs great other than a little hesitation when you take off from the light. It had new ac plugs put in it a few years ago. Just noticed that the carb has a little leak from the front of it. The car is pretty much original except for the 3" flowmaster exhaust. Pollution tubes on the exhaust manifolds on both sides have some holes in them, are there any replacements out there? Always had fuel stabilizer in a full tank when stored. Started every couple of months, more often when it's nice out. I know it needs some love, would like to drive it after I replace the BFG comp t/a's from 1998 and do some minor work to it like the valve seals and the carb leak. since I am on a budget. Having a 14 yr old son does that to ya. Any suggestions out there? Please keep in mind that I'm on a budget and would like to keep it original. I appreciate any help/suggestions that I can get. Thanks in advance.

 

I have a clean solid spare set of those tubes if interested. Get me your email address for pics and other info
Henry

 

Have the carb rebuilt and make it ethanol compatible at the same time.
You can get umbrella valve seals from Alex's Parts. Might as well change the valve springs while you are in there.
Call Alex and talk to him directly. He tell him what you are doing and he will take care of you.
https://www.alexsparts.com/sbc-z28-v...-500-max-lift/
https://www.alexsparts.com/11-32-umb...51c-universal/
Get some rubber over steel core valve cover gaskets.
Your vacuum lines are probably hard. Replace them.
Change all the fluids. Todays oils do not have enough ZDDP for your flat tappet camshaft. Choose an oil designed for FT cams, or use an additive. See attached. You might want to upgrade to 1.6 rockers for a little more valve lift (if you have enough clearance). You can get stock type 1.6 ratio long-slot rockers for cheap.
Inspect/replace your flexible rubber brake hoses.
I'm sure I will think of a few more things.

 

I also have a 84 HO Z all stock with 180,000 miles. Carolina car, no rust,
Typical southern car with a case of southern sun burn yet clean and shiny!

I recently replaced my valve stem seals to cure the start up puff of smoke.
Smoke puffs gone and she don't use a drop of oil now!

No need to replace the valve springs and keepers UNLESS you pound it
and shift at 5500 redline all the time IMO.

No need for the SNAKE OIL treatments either IMO.

Since shes old and high mileage I use straight 30 weight oil.

She sleeps in the garage here all NY winters and I drive my old
94 Buick winter rat or my 13 Impala.

As far as the air tubes your best bet is the parts yard.
But they are usually gone/butchered and hard to remove and the
easiest way is to just take the whole exaust manifold off the donor
car and swap them.
My 84 still has all that stuff and its in good shape and operating.

As far as the carb its prob. the lower throttle plate butterfly bushings
are shot and leaking thru there.
Just inspect closely as it may be the gasket from the bowl to the
throttle plate or the factory passage plugs in the front of the carb.

Good luck and keep us posted.

 

If You Can't Find Used,New Tubes Are Still Available.