Correction on my post. I have the Turbo 400 tranny, that will hold up easily.

 

sounds like my 84 z28... ijunked my 305 and the t-5 blew up so i droped a 350 lt1, turbo400 tranny and a bunch of other goodies.. your best bet would be to find a 350 block and just build it... reliable..powerfull.. and not too expensive thats what i didand i ahvent had any problems with the motor yet.. ijust gotta work on the interior and exterior