I am planning to take my 68 coronet with the factory 225 out to my local drag strip to see what it can do. I have set my points to .020, set my valve lash to .021 exhaust and .011 intake, I have rebuilt my distributor, rebuilt my Holley 1920 carb, set plug gap to .45, set my timing to about 12° before TDC and replaced all electrical system components. I plan to run premium gasoline with NOS octane boost. I would like to know if there's any other little performance tweeks I can make for a better 1/4 mile time. And if an octane boost and premium will make a difference if any.
Anything anyone knows that will improve engine performance is much appreciated.

_________________
1968 Dodge Coronet with the original 225 slant six and a904 torqueflite transmission. One family car with 67k original miles and mostly original parts.

Don't waste your money on the octane boost. Most likely it would also run better with 89 octane, then 93.octane. A stock slant has such a low CR, it doesn't need much octane, and the only reason I suggest 89 octane, is because I have no idea what curve is in the distributer.
I would put the plugs back to .035, unless you have a non stock ign system. I found my stock slant ran best with a little tighter valve lash. Maybe .008 intake, and .018 exhaust.
Haven't worked with points in a long time, but it seems like .016 is a better number, if I remember correctly. You don't want the gap too wide.
1) make sure the carb opens all the way, when the pedal is on the floor.
2) make sure the choke is fully open
3) Remove the fan blade, but make sure you don't let it run hot
4) You can also remove the field wire from the alternator, but don't let the battery get low.
5) remove all excess weight in the trunk, and back seat, including spare.
6) if you want to speend the time/money, cut the exhaust pipe, and have a pair of flanges installed, so you can open the exhaust at the track.
7)Raise the front tire pressure to about 35lbs.
8 ) stay out of the water box, if on street tires.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Thanks for the advice, I do plan to pull the spare tire and jack. I am running stock ignition but I found the the larger gap on the plugs did make a difference, along with pulling the plug washer to get the ignition a little further into the combustion chamber. The stock specs for the points are .017-.023 and everyone was saying to run .020 or a little under, and mine is a tight .020. Again thanks for the advice.

_________________
1968 Dodge Coronet with the original 225 slant six and a904 torqueflite transmission. One family car with 67k original miles and mostly original parts.

Add air to the front tires to reduce rolling resistance and better roll out. I would play with the timing till it pings and back it off a couple of degrees. Oh yea, add a 200 shot of nitrous! Just kidding. Let us know what it runs.

_________________
Hyper_pak

I have friend that for a while was into street racing... (shame on him) He said he would put dry ice in the air filter.... Said he could tell the difference for sure...
Is this true?? or is it just his myth??

_________________
Slant power!!!
At least I try...

I don't know about dry ice. It might cool the air coming in, but it's also gonna give off CO2.

I have another idea that should work. Buy one of these, and a box of these, run a rubber hose from your air cleaner through the firewall, attach to the nose of the dispenser. Pull the trigger as soon as you get off the line.

I wouldn't recommend trying to reload mid-run, but you can probably crack multiple canisters into the dispenser at a time before discharging.

_________________
Somehow I ended up owning three 1964 slant six A-bodies. I race one of them.
Escape Velocity Racing