65 gto 389 ws engine stock
 

Anything "minor" I can do for more power in 1/8th mile. Runs upper 9's low 10's. 093 heads, 068 cam, tripower, 3.36 posi with 4-speed. All in good condition.

Distributor recurve.

Running points& condenser?

Loosen the belts a little when you make the run, maybe even use an electric fan. Run electronic ignition if you havent already. :2cents:

It depends on your definition of minor?
First and for most, get the car on a chassis dyno run by a good tuner!
How's your wallet also?
Your rear gears are no where near enough for 1/4 mile racing, no less 1/8 mile. If you do. Not want to stuff in 3.55 to 3.90 rear gears at least put a shorter set of tires on the back!

Remove the front sway bar links and or the front bar all together for more front end rise and it greater weight transfer to the back and less overall vehicle weight.

Install a X pipe in the exhaust system.

If you are still running on the stock valve springs, than it's high time to change them out to help the motor rev faster, and while you are in there add 1.65 rockers, but do not use poly locks on the stock rocker studs, use a shaved down double nut set up so you do not snap off the rocker stud tops.

Add a two in let duct tri power ram air system and re jet the carbs for greater top end mph.

Install a alternator cut out switch to use on the pass down the track which will net you 1.5 to 2 more HP, just make sure your battery is a bigger than stock CCA rated.

Install a aluminum driveshaft, and while on the subject of that and for your own safety, install a driveshaft safety loop!!
Take off the power steering belt if so equipped.

Fill up at the race gas pumps and advance the timing. 100 octane is enough.
Alignment, tire pressure, drum brake adjustment (no dragging shoes)
Drag slicks.
1.65 ratio rocker arms.

Keep on mind that unless the heads have been modified to accept 1.65 rockers they're not an option here.

They are not an easy bolt-on, pushrod slots need to be elongated or eliminated altogether along with the installation of screw-in rocker studs and pushrod guideplates.

The 389 heads use a machined slot in the head to guide the pushrods, not a separate stamped steel guideplate from the factory.

Yes

Not too expensive but like steve25 said the best way is to lower the rear gears. It will show the biggest improvement.

IA2
Billet crank
Solid roller
Tiger heads
Procharger
Lenco

DONE. All with the stock drum brakes, no sweat. Have fun. Buy life insurance.

Just to give an idea how far the power tuning is off on your 65 3x2 4spd 3.36 -

A friend of mine had an old 70 Chev Shortbed P-U
pretty mild 350 4bbl Qjet , 3spd stick , 3.50'ish gears non-posi , tall 15" mud grip tires
ran same numbers in 1/8th as you posted.

have your ignition and carbs calibrated 1st
polish driving/shifting skills
go low 9's or high 8's