RattyDesoto

Let me start off by saying I'm new to big block and even newer to mopar's in general lol. I've always had/built screaming rev to the moon small blocks. I'm mainly a ford guy by heart but love anything unusual. As things sit right now I have a nicely built 90 mustang GT that I'm debating on trading for a 1955 desoto. The desoto has what's susposto be a freshly built 440 making somewhere between 550-575 hp. How easy is this to do with a 440? I'm guessing its .30 over , still cast heads , 650 carb and intake and a 600 lift cam. I know when I built my 455 with similar parts I was only at 490hp and had to run a 750 holly. Further more , what's the most one of these blocks can take?

Doubtful that I'll ever push the block to it's limits but I'd like to know it's safe zone. If I get it I'm thinking about throwing a supercharger and nice heads on it. Kind of like to know what it's capable of.

RattyDesoto

This is the info he just gave me on it:

Lower end was rebuilt before I got it its 30 over all new bearings and seals new high performance oil pump eledbrock timing chain Mopar purple camshaft around 580 lift not 100% about 9 1/2 to 10-1 compression heads were redone a buttons machine shop 202 160 valves block and heads are 1974 interceptor motor...new valve seals dual valve springs new Molly push rods holley street dominator intake 750 quick fuel carb manual secondaries and fully adjustable lokar cables holley mech fuel pump 3200 stall with a tci kit in the trans offenhauser valve covers...the same motor setup in my buddys 71 dart on 10" tires ran a 10-2 in the quarter my motors been together for 6 months and in the car for 4 months always inside..has Mopar ignition with socal ruby red plug wires e3 sparkplugs super comp fender well hedders

moe7404

the 440 does not need high RPM to make power. some guys in my car club call them tug motors. if it was mine the mech fuel pump would get tossed. and go to electric fuel pump near the fuel tank. with a overide to pump up the carb before starting, saves starter, bat. all so iam guessing it has an aluminum torqueflite, ie bolts to a 440. i have seen Funny cars in 60s push 15,000 HP into aluminum TF. is the one to use. the castiron tourqueflites of the 1950s will only hold 380-400 hp max. but in reg cars was good enuf. i would NOT be afraid to own the car.

Skwerly

the carb on a 440 making power like that is probably bigger than 650. my guess is 750 or even 850.

RattyDesoto

I'm buying it as a project car for me and my girl. Just wondering if you could really get 550-575hp from a .30 over 440 with a little head work and a good intake and carb. Like I said , I'm mainly a small block ford guy but the average set up there .30 over 302 , aluminum heads , good intake and custom cam your only 360's. obvisouly bigger cubes = bigger power. I just don't know 440's enough to know to what extent it is making , or could handle.

moe7404

try to find a factory paper manual for the year of the engine. i most likely have 3-4 of them but they are NOT for sale. i remember when they came out in 1966. dont for get not ALL 440s are HP. if i remember the factory color tells you if its a REG of HP, for most years. but on chrysler stuff there is all ways exceptions.

Moparbob

While 550-575hp is fairly easy to get from a 440 on 91 Octane "Pump" Fuel, it does NOT happen with the usual simply bolt-ons like Intake & Carb, with a "little Head work" ?
(FYI.....the bone "stock" Valve Sizes on most BB Mopars is 2.08" and 1.74", so the fella's claims of "2.02/1.60" is incorrect.)
Nonetheless,
a 550-575hp .030 over 440 involves the RIGHT Pistons,(nothing cast jobber that I know of will work), Aluminum Heads with work or EXTREMELY highly modified Iron heads with 2.19"& 1.88" Valves, and a conduscive Camshaft that WILL REQUIRE AN ADJUSTABLE VALVETRAIN.
The Valvetrain should be the dead nuts giveaway if the guy is telling you anything credible on the current Engine....because ANYTHING running anywhere near .580"to .600" Lift WILL have adjustable Rocker Arms on it already. Pull a Valve Cover and check ??
600-650hp with main Studs is about the reasonable limit over the long term for the stock Blocks.
650-750 & 800hp with Studs, Girdle and Billet Caps being more long term band-aids than anything else over time...but they will live awhile.

moparted

I wouldn't be conconerned if was an hp engine, its rebuilt and the parts that made it a hp have been replaced

inri

Ratty, the power will come from the heads IMO. Since the engine is a big air pump you'll need solid heads to flow the air to make power. Cast iron heads can produce those numbers on a 440 but they need alot of work. 500+ hp is basically a give in with a little port work on a 440, and 500 lbs of torque as well. To get to 550+ you'll need a good matching intake and carb as well as a bottom end to support the added power. To be honest, 500-525 hp is about what one should expect from an "average" 440 rebuild.

I would definitely go with aluminum heads if you don't already have them. Gain 50-150+ more hp as a bolt on with some port work, as well as lose 40 lbs of top nose heavy weight!