I have a nice spare .030 over 383 block, and new 3.75 crank ready for a b engine.

What combination would be the " ultimate" for a performance engine?

Heads?

Header size?

Compression?

Roller cam?

What could I expect out of this engine in a B-Body that is about 3600lbs?

ultimate what....street? race?

my 383-->438 is a great street motor and will simply get a refresh and maybe some port work on the edelbrock heads that it has now.

flat top pistons for 10.5:1 compression, OOTB Edelbrock RPM heads, RPM dual plane intake, 750 HP Holley, and a Comp XE-275-HL hydraulic roller. made over 500 hp at the crank, and I could jump in it any time of the year and take it on a 5 hour road trip.

B1 top end, .650-.700" roller cam, gear drive, 1050 Dom, 2" headers

Or Stage V conversion heads

$$$$$ Chris (440pursuit) made well over 600 w/ an iron headed (indy I think) 431. You'll need the best heads you can find/afford, roller cam and as much compression as you can. I'd probably look at going boosted as the drivabilty is much better. If you go N/A you'll need 12.5:1 and that means race gas or at least a water/meth injecton kit. What is your goal?

431 combo will react like a 446 just a couple hundred rpm higher. I would use small port heads for the street because you're torque peak will still be well over 4000. For a bracket motor I might go to the next size heads but The rpm would go up about 1000. B1 heads may have problems with a 4.280 bore? At any rate the b1 head wouldn't start working till somewhere around 5000 rpm and would make peak power at over 8000 rpm. 383 blocks aren't very strong from what I hear.

A 431 or a 451 is really (more or less) an "optimized" 440...a 440 in a lighter (both in terms of overall mass and especially bobweight) packaging. So any strong 440 RB combination will work just a little bit better in a B based low deck version.

No need to Reinvent the wheel, the 426-440 RB has been the Mainstay of Mopar Bracket racing for 50+ years and there's still a LOT more 440 based bracket cars out there laying it down every week-end. So IMO there's nothing "mystical" or "magical" about a B block or any combination you build from it, it's just a little bit 'better' version of what has always been a very good and strong Engine.

I built a 431 well over 25 years ago using an OEM 454 truck piston and bushed rods, semi "exotic" for it's time I guess. But we did it get them to "sucker bet" against my little 383 but it really didn't run much better than a 440 with the same CR and Cam. I always liked 451's but more for the smaller packaging in A bodies because even 30 pounds was an advantage over the nose in an already nose-heavy (compared to a 340 anyway) combo.

Today with stroker kits and especially the heads out today the low deck advantages (relative to the cost of doing a comparable, ie light piston 440) is significantly less than it used to be. Nothing against them at all, and I've built more than many people have...but for reasons I can no longer defend other than for sentimental preference. Today, to me they're absolutely PERFECT for Road Runners and Super Bees and the other perfectly good oem 383-400 based cars out there, I just wouldn't go out of my way to build one anymore if I already had a 440.

So for an 'Ultimate' combination....just look at what already works the way you want or need it with a 440.

Ultimate? For a 431 I think that means a strong, simple cost effective sleeper. With that definition, I'd put Edelbrock or 440 source heads at least prepped and better yet fully ported. Compression and 10.2-10.4 with tight quench. Cam in the 230-240 degree @.050" range. Roller is nice, however flat tappet (mechanical) would be OK also with high zinc oil and correct break in. If you are mainly racing it and can get along with a high stall convertor, 10 degrees bigger on the cam would give more power.

For the quench, pick pistons and/or machine the block for zero deck and use a common .038-.040 gasket. Perfect quench. The Felpro permatorque head gasket seems to work well with aluminum heads on BB's and is cost effective.

Something like the above should make 450-500 HP.