Any guesses as to how fast this old Cuda might go ??

OK here it is, a 68 Barracuda fastback ( see album ) I put a old 400 (cost me$275 Canadian ) in it about 1978 vintage I believe. I had some problems with the 383 and got pissed off and yanked it out. So then I put new comp cams valve springs in it, my Hemi grind purple shaft cam , new chain, gears, hi volume oil pump. Then topped it off with a Edelbrock Torker intake and a 750 vac secondary Holley . I have 76 jets front and rear with a nice light spring to open the secondarys. Mopar Electronic ignition with the orange box, some light springs in the distributor so it reaches full advance pretty much after it fires up, which I set at 33 degrees, at 3000 rpm. A set of headers, ( b body slightly modified with a little TLC with a ball peen ). Auto trans with a 3800 convertor, and 3:91 out back, I will be running a 26.5 inch slick on it. This motor has about 80,000 miles on it . It has quite a bit of blowby also , but man does it pull. I can not believe how good this old thing runs, it just seems to be a good combo. I am hoping to hit the mid 13's with it ? I can zing it up to 6400 rpm and it keeps pulling , although I only did that once, I am headed to the dragstrip on August 7 th and don't want to blow it up before I get some timeslips out of it. I have been shifting it a 6000 rpm, which seems to be about right. I have this guy around town with a 63 chev Impala who wants to run me real bad so we are supposed to go up to the track and have it out. It runs 14.0 so he says . So have to be able to beat him. Any guesses guys as to how fast this thing is gonna go ? Anyone have a similar combo and have some estimates for me ? Help, I have to beat this dick and his Chevy.Fast back383