Interesting thing can build a 10:1 run of the mill 390 with TFS OFB heads, a hyd roller cam, and an Perforner RPM intake and make 500 hp. All easy to find stuff and not stupidly priced. Makes one wonder why both with 428 blocks and strokers at that level.
I will throw my opinion in, it's free and worth every penny
Assuming the same quality of parts and machining are used for both in other areas, the difference in cost is:
- Crankshaft - add 450 bucks assuming you mag and turn the 390 crank
- Balancing - add 150 bucks for internal balancing
- Connecting rods - subtract 150 bucks for BB connecting rods
The rest is really 1 for 1 assuming a build at the same level, so that's about 450 dollars more.
A 396 at 500 HP would be 1.26 HP per cid, a 445 would be 561 HP at that level, and a 462 could be 582 HP, however if the goal was similar, you could build it it much more well mannered. A few 445s and 461s in the dyno section that do almost exactly that too
Hard to beat a stroker with good heads. One thing to bring it down is stock rods, stock crank, cheaper TRW/Speedpro pistons. However both strength and potential valve clearance, not to mention power loss of a less than optimum piston/ring combo might not get you to your 500 with a 390.
One thing I do agree with completely is the value of a 445 vs a 462. If you have a 428 block, a 461/462 is a real nice piece, but for those without a block, the 445 can be a very wise choice just for the difference in the cost of the core itself