Better listen to Perry on this one Byron. I know I've spent just about 1/2 as much money on my car making it run straight and hooking hard as I did on the motor. Part of my required upgrades are safety stuff the NHRA has mandated to me, and my car is on a 99/100 wheelbase. And for goodness sake please understand that a Cobra is NOT a street rod. It's a all together different animal.
Remember too that aprox. 1/3 to 1/2 of the original Cobra owners that owned these cars either totaled the car or killed themselves. And they thought that they "knew" too!
That being said I liked the old Stallions. Nice thick bodys and frames. For drag racing the stock Stallion frame will flex at the back from side to side. You need to look there for safetys sake. When you are done with this project, it's going to weigh more than you will want to admit I'd bet. That's O.K. though, mine is a bit on the high side weight wise too. At least by Cobra standards anyhow.
Good luck on finding a manual trans. that will live if you choose to buzz that 429 motor hard. I think I'd be calling around on that one, and be prepaired to spend some change. That's mainly why I went to a auto in my case. Good luck with your project. BTW. I see you chose B.T. Chevy port heads. Good choice, I'd say.
cobrashock