How to get 400 hp out of 1971 340 .30 over

I GOT 410 HP OUT OF A 340 30 OVER Mahle flat top pistons Ede heads 11:1 compression not sure the cam think it was 573 lift . My new 340 makes a bit more 440 hp , using Trick flow heads Molnar H beam rods speed pro flat top pistons 10.5 compression , could not find the nice light Mahle pistons , 1.6 rockers ported Ede dual plane intake and a 750 Street Demon . 400 out of a 340 is easy with the right parts and builder
Machining these days and most parts are much better . Back in the 70's me and a friend both bought 340 Darts one was 1/2 a second slower no matter who drove it . back then it was pure luck if you got a 340 . They just slapped them together , did not care s long as they started and rolled off the line , then talk about panel alignment , or lack of