looking for 425 hp

[triple black]

I have a stock 400 w/ 1500 miles on it in my '70 Chally.  I'm thinking of converting the car to a 4 speed and upping the ponies to 425.  I want to do things right.  I also don't want to spend any more than necessary.  I'm looking for suggestions to reach the 425 hp w/ the least expense.  Can it be done w/ a stock bottom end 400?  I have a set of 915 heads waiting to be reworked.  Do I need to stroke it?  Will just the reworked 915s, dif cam and pistons do it?  Should I scrap it and get a 440? 

[Chryco Psycho]

I did a stock 400 in a 68 GTX , the bottom end was untouched , we used ported 516 heads with 1.81 exhaust valves , Headman headers , M1 single plane intake & a 750 Holley & an Engle K58 cam ground on 110 CL & it ran 14.4 on street tires at the local race track with traction porblems & at 4000' altitude so it would be a 14.0 at lest at sea level & it ran over 90 MPH & was using 3.23 gears , on the dyno it made 252 RWHP  at 5700rpm & 244 ft lbs peak & held 235ft lbs from 4000-5800 RPM , gross rated that should be around 400 HP with a wopping 8.6 :1 compression ...... so if that is enough power copy that combo ,
 stroking it will  add a lot of torque

[A383Cuda]

252 dyno rwhp = 400 hp?! Wow! We sure do lose alot in the power transfer don't we. Too bad we couldn't just do away with everything else and just strap a bucket seat to the top of the carb cleaner.

[Chryco Psycho]

depends on the dyno , I use the Mustang , it has a lot that can be tested for & it reads the lowest of virtually any Dyno