Hmmmm. I would call it a good running car, but not good power. Unless the A body weighed 4200 lbs, or the DA was 10,000 ft, that motor does make good power IMO. Of course the details matter.

Ran it @ Keystone about 3600 w/me back then. I'd say around 400hp or less.

In my opinion you should move forward with the 440. I think you want to regardless anyway.

Thats kinda how it seems to be. The 383 has all the mods done to it to make more power. INtake, Cam, Headers, EFI, heads. And like I said the best we got out of it (remeber this is a street car) was 300 WHP. Ideally the 440 would be rebuilt and new pistons installed, but it has recent rebuild on it so why not just go with what it has???? Will it make less power than the 383 with the same parts on it? I doubt it.

The new setup will look more like this
low comp 440
520 ish lift cam- forgot duration
sinle plane victor intake
tti headers
sniper EFI
stealth heads
the car remains the same as

3500 stall
3.73 gears
65 b body

Will this be more of a tire shredding build than a 383 with similar engine parts and the same car setup?

Maybe you could swap out the pistons. I believe 2355 piston weighs about the same as the 1.99" and 1.91" CH replacement type pistons

The 440 will have more low end torque but if the 383 has more compression and the cam, heads, induction,etc are identical the 383 will make more HP.

I’d do some measuring & calculating before buying any parts.

I recently prepped some 75cc E Street heads for someone looking to update their stock bottom end MH 440.
The pistons were down the hole .165”

Here’s one that was tested last year:
https://www.forabodiesonly.com/mopar/threads/another-very-mild-440-build.482202/

A better manifold and a bigger cam would have woke it up a bit more.

before deciding I would do the math and work to figure out exactly how much compression the 383 atually has, mabe the same thing on the 440 motor and go from there
The Stealth heads have had two different combustion chambers sizes so if you have the smaller 80 CC versions it may make enough difference on both motors true compression ratio to help you decide
A 9.0 to 1 compression ratio on a 440 compared to a 10.5 to 1 383 may end up making the same HP with a larger increase in torque on the 440

383 and 440, 383 + .030 pop up pistons 0 deck height, 67 stock heads, a ton of compression, 509 cam, torker intake 750 DP. Ran 7.0 1/8th. 440 dead stock (74) low compression, 452 heads with a little bowl cleanup, same cam out of the 383, torker intake 750 DP best was 7.59. Same adjustable rockers on both, same stock (spacer) electronic dist and MSD 6, same coil. 3800 vert and 4.88 gears 14-32 slicks on both cars. Now 383 was in a Dart and 440 in a 64 all steel Savoy. Maybe 200 lbs different
My conclusion, you can’t beat compression.

And the differences in ET and MPH was Oops, ET was .6 in the 1/8 mile
How about 60 ft. times?
My BB 1969 Dart GTS weighed 3100 Lbs. without me in it, my lightest 1963 Plymouth Belvedere weighed was 3420 Lb, no heater, radio and with light weight Crager Super trick wheels and race tires on both cars Best ever on the Plymouth was 11.23 at 119.+ MPH, the Dart best was 11.17 at 122. +MPH
100 lbs. added on most cars equals .10 ET in the 1/4 mile
BTW , were both cars tuned to for best performance at the same track and similar weather conditions?

Didn’t have 60s when 383 was run but was within 2.5 tenths of a well built 440 in the Dart. 383 was making right at 400 hp (118 mph 1/4
in my Duster) 1.50 60 with the 440 in my 64 on 93 pump gas. I doubt it was making 350-375 hp. Both on engine stands at the moment.

No question, I'd use the 440.

Totally different applications. At that level of compression, 3-4% per point is normal (apples to apples displacement). In reality, the 440 has a big bump on power (0-5250 RPM) already on the 383 out of the gate if everything else is equal, so that's not really a good comparison.

383 will peak likely around 5,750 - 6,000 RPM.
440 will peak likely around 5,000 - 5,250 RPM.

At the end of the day, regardless, Torque x RPM / 5252 = HP. Where do you want your power curve?

383 would need more gearing and a higher stall, but HP is HP. On the street, you would - if I dare say it - be better off with LESS torque at low speed. Low speed torque is fun though, so it's a trade-off. Less likely to have problems with an engine that peaks well below 5,500 than one that needs to wind out to 6,250 - 6,500 to make power.

Also, 440 source heads - they are essentially an aluminum OE replacement. Yes, they flow marginally better OOTB (20-ish HP) but really, same cam in both, the 440 will make much more power over a 383 from 0 - 5,500 RPM.

Even after the 440's HP peak, it will still take some RPM (time) for the 383 to make up the 50-60 ft/lb deficit it has against the 440.

So, my vote - 440. Don't worry about the compression, Stealth heads - Performer RPM intake manifold - .530 to .550" lift / 230-235* duration / 110-112 LSA Hydraulic Roller. 3.55 - 3.73 gear. 3,200 - 3,800 RPM converter. Great street car with plenty of power.

Yes.