273 said

I was estimating based off this 323 that makes 477 hp @ 6500 roms and 427 tq @ 4,900 rpms, making with a decent 1.32 lbs-ft per cid and 90% of of peak torque at peak power.

He just needs to find 18 lbs-ft @ 6,500 rpms to hit 500 hp (404 lbs-ft) from the 477 hp (386 lbs-ft).

https://www.motortrend.com/articles/0901phr-mopar-318-magnum-engine/

RPM	TQ	HP
2,500	337	161
2,600	350	173
2,700	357	183
2,800	357	190
2,900	356	196
3,000	351	201
3,100	345	204
3,200	339	207
3,300	343	216
3,400	356	230
3,500	371	247
3,600	385	264
3,700	396	279
3,800	404	292
3,900	410	305
4,000	415	316
4,100	418	327
4,200	420	336
4,300	422	345
4,400	421	353
4,500	420	360
4,600	421	369
4,700	425	380
4,800	426	390
4,900	427	398
5,000	427	407
5,100	427	414
5,200	426	421
5,300	425	428
5,400	423	435
5,500	421	440
5,600	419	446
5,700	417	453
5,800	415	458
5,900	412	462
6,000	407	465
6,100	401	466
6,200	397	469
6,300	393	471
6,400	390	475
6,500	386	477

Click to expand...