Looking for advice/insight on car

Long time reader, first time poster. So after a few years for putting my car together I've finally got it to the track a few times. Here's the specs that I can remember on the car

1974 Dodge Dart Sport
A freshly rebuilt .030 over 383 with comp cams XE285HL, torkerII intake, MSD 6AL-2 box with Pro Billet dizzy, stock 906 heads, 750 VS holley, breathing through just a set of headers and nothing after them. (The engine was built to follow Mopar Muscle's resto to rad 383 build, suposedly it was said to make ~450 hp and 450 lbs/ft)

Trans is a 727 of unknown mileage with a transgo TF-2 shift kit, and 3500 stall 10" Turbo Action torque converter.

Out back is a 8.75 donated by my bothers 69RR with 4.30s and a limited slip spinning 275/60/15 MT Drag radials.

Suspension is stock 318 bars and springs with cal tracs and Single Adjustable QA1s at all 4 corners

The car weights 3296 with myself in it.

As for performance the last time out with the 4.30s it was running 13.2@104 with a 2.04 60ft.
Now I know that being a new driver has an affect on all this but my buddy, who has a few more years of racing on me, couldn't cut a faster time then me in it. And at the last run I made I got flagged for leaking trans fluid, and was a 13.4@102 and a 2.06 60ft, it's coming from the inspection cover area so my guess is that the front pump is leaking but I haven't pulled it yet. My plan is to have the trans completely gone through by a racing trans guy and see what he can find and upgrade.
Its my thought that the trans is weak link here because, well it's leaking, and it is the only thing that hasn't been gone through other then the limited slip which also might be on it's way out too because there just wasn't much smoke in the burnout box and my buddy thinks he noticed noticed the driver side tire slowing down and speeding up during my burnout.

So my question to you of the internet is that; am I thinking to optimistically of my car to think that it should be quicker then a 13 second car? Thanks in advance for the help/advice!