which is better? 68, 73 440

[red79]

Hey, I have an opportunity to pick up a complete 68 440 for $300. Never been bored, but the rotating assembly is frozen. pulled the heads off and there's some slight surface rust on the walls. Figure a good machining would clean it up fine.

There's also a 73 440 available for $400, was running when recently pulled, also never been bored.

Looking for some reliable big inch power for my street use third gen. My plan is to put together a standard budget 440 combo, hoping to turn around 400 hp. I like the sound of the forged crank and 906 heads on the 68 for starting a build, but I'm a little worried that it's frozen.

Grab the 68 and give it to the machinist? or jump on the 73? what do you guys recommend?

[Chatt69chgr]

A piston is probably stuck in the bore of the 68.  And you would get a forged crank with it.  Also internally balanced.  906 heads will need hardened seats in exhaust side.  cast crank in 73 and externally balanced.  depends on what you want to do with the engine.  can't get good performance pistons w/o boring to 30 over.  so both probably have to be bored.  one may be cracked somewhere.  won't know until you test it.  I think around 73 was when they went to a different center main bearing with larger thrust surfaces.  how are the engine mtg ears.  sometimes, they are broken.  if both appear ok, maybe get both and have a spare block.  what does your machinist say?

[John_Kunkel]

Not all '73 440's had a cast crank. '74 was the change in the center main bearing.

For a hundred bucks less I'd take the '68.

[RD]

me, i would pick the 73 block knowing its not seized.  a $100 is not much of a gamble when sleeving one cylinder costs $100.  a frozen block, its a enigma.  you do not know what you are getting into.  you could have to sleeve one or many cylinders, then you will wish to have just bought the 73 block.  free and easy rotating assembly is insurance if you ask me.

[Cooter]

For that kinda money, I'd buy both .....A 1968 440 round here goes for at least $500.00 for a rebuildable core...

[red79]

i'd like to pick up both, but i'm currently budget limited--just want to pick up the good deal before someone else does, and take my time getting the rest of the parts for the build

my machinist recommended the 68, mainly for the internal balancing... I think i'll end up going with the 68, despite the uncertainty of the bore quality--if after the tank it turns out to need sleeving, I still get a set of 906 heads, intake, steel crank and maybe some rods out of it + a few hundred pounds of scrap.

plus the same guy has a couple buildable 68 and 75 bare blocks he'll let me have for a hundred or so if it comes to that.

mostly just excited to finally start my engine. the 400 under the hood now is tired, and has some nasty rattles inside the crankcase. I think the previous owner was running a 100 shot of nitrous on it that beat it to hell 

[firefighter3931]

I'd go with the 73 motor if it has a forged crank....pretty easy to identify by looking at the balancer. 

The heads will already have hardened valve seats which you would need to install in the older 906 heads and flow just as well. 


Ron

[red79]

Just went to have a look in person, and got some new info. looks like half the bores on the 68 are badly rusted, probably nothing that a 0.030 cleanup couldn't fix, but no way to tell yet. no oil pan, accessories, brackets, either. but he said I could have it for $200.

turns out the 73 came out of a motor home, with around 70k miles, and looks like it has the forged crank (pic of balancer attached). It's also complete pan to intake, with all accessories and brackets still attached--there's even a cruise control on it, which i'd never seen before. now I think i'll go with the 73 for the budget build, since it won't need new seats any may not even need crank or rod cleanup. the $400 i'll pay at the outset will immediately be offset in savings on machining and parts.

is there anything I need to know about using a motor home 440? for example, are there any mounting differences vs. one for a car?

[RD]

no mounting differences, just use the appropriate engine mount brackets for your vehicle.  the 73 engine mount bosses are actually thicker, which is a plus.  you will need a different oil pan/pickup i can pretty much guarantee that.