Get the convertor built for that application. it will be worth way more then a gear change. I have a 3000 pound 7.00 1/8 mile car with a 363 sbc and glide. It's 60' is 1.41 your short time is pretty slow for that e.t. the turbo trans has a lot more torque multiplication then a glide and the convertor that was right for th trans is drastically wrong for a glide. I've been there before. Give neal chance a call.
steve,