This deal will need a lot of help . the weight and altitude are killers. I calculated 4300 weight and 13.00 et to come up with a hp figure of 385 crank hp. To run the number you will need to do cam, heads, headers , high stall converter (4000 rpm or more) at least 3.91 gears and slicks to get there. If you spend the $$ to get heads for your future build you can gain compression and airflow big time. Check out MARSH PERFORMANCE sidewinder heads. Todd is great to deal with and can help you with a cam also. The plan IMHO should be to spend the$$$ on what can transfer to the next motor. The 400 is the motor you want to stroke. A 499 cube stroker that has 10/1 compression can run on pump gas with aluminum heads. And 500 + hp is a piece of cake.