yeah, according to your speed you should have been about a 13.4 maybe even a little lower!

Did you run both lanes? Sometimes even though the posi is working the track will trick you into thinking it isn't. Most the time this will change depending on which lane you've got. Or how the water box is set up. If you tracked perfectly straight out of the light, chances are good both wheels were not spinning close to the same rpm.

The cool thing is both your speed and your ET will improve with traction.
What kind of tire pressure where you running?

Might be time to change the fluid and additive.

If you've got a manual shift body (easy to make), next time lock it into second for the start. with a 3k torque converter it won't bog.
Also remove your sway bar at the track, and get some 70/30 or even 90/10 shocks this will be a big help on weight transfer.
After that I would suggest a fully enclosed trailer/shop, with welder/generator, chief engine tuner, clutch man.......

Just watch out this stuff is really adictive and way more expensive than being a couch potatoe or bench racer.

Spray the heck out of your wheel wells with Pam cooking spray at the track, this will make clean up much easier.

 

Ran both lanes... the left one seemed better to me.

25 psi on the back tires


I stayed out of the waterbox (street tires) and was carefull not to get the tires wet.

Fluid and additive were changed out last October

And no track teams for me! I just want to be able to nail a stock LS1. (I know a few people running them, and they believe they are God's gift to the automotive world!) It really pisses them off when I remind them I'm running 37 year old technology, and the best they can do with all the computer controlled air/fuel ratios, huge tires, aluminum block, better gearing, etc.. is to just barely beat my antique car. (which I hope to remedy soon)

 

You just need to let them know that without the technology of your car back then, they wouldnt have the technology of thier car today.
They dont like that either.