400 Build vs 440 Build

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roughidle

roughidle

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So, initially I had every plan to build a 400 block up to a stroked 500 +/- motor and my initial reasoning behind this was because we had a 400 sitting in the back of the shop and I figured in an A-body (I'm building a '68 Bcuda notch) it would save me an inch or so in height under the hood.

But - my question to you the masses is whether there is a benefit or hinderance to choosing a 400 over a 440 or a 440 over a 400. I'm planning on ordering a 440 source stroker kit in either case, but wanted to hear everyone's opinion if there would be a better direction to start with.

I'm building a car that I will be driving around town, a few local car shows, and then I'll be running at the strip maybe one or two weekends a month for a few of the warm months during the year.

Thanks.
 
I like the 400 block for the slightly more compact package and they are supposed to be stiffer than the rb. I would build a 451 or 470 over the 4.15 stroker. You get more piston skirt and ring package not intersecting the pin. Either can be built to well over 500hp in a street friendly tune.
 
That's sort of the direction I was thinking of traveling just for the reasons you stated. Shorter package, Slightly more sturdy, etc.

Everyone else - feel free to chime in. I'd like to get as many different perspectives or reasons as I can.
 
the 400 block for sure, especially since you already have it in house. it's tougher and a few pounds lighter also.

add a 440 forged crank (mains cut down + chamfered bearings matched) some kb 251 pistons (about $300) you get some cheap power. still use the 400 rods. only issue is watch you don't get too high with the compression (what heads are you going to use?)
I don't think the 440source kit is worth the extra money to be honest, over purchasing a 440 crank and getting it machined. $200 to $300 maybe for the crank & machine work.

I just stayed with my 400 (no stroker), added kb240 pistons (9.5:1 compression), had the block zero decked. yeah I will miss that extra 51 cubic inches but I will not have to worry about using pump gas at all.

where are you in PA? there is a shop here that are gurus with head porting, and they now do BB as well. http://www.shadydellspeedshop.com/ one of the best right there in PA. if you are in southern PA near the MD line I could suggest some smaller shops that are professional.

the only 2 disadvantages with a 400 vs. 440 is at the upper limits a 440 can be stroked to more cubic inches with the biggest stroker kits. also the heads are the same, but the 383 & 400 intake is a bit narrower I think, so your choices are limited.
I'm using an eddy performer rpm, since there is a 383/400 version.
I've heard with the top end intakes people can cut a 440 intake to fit a 400. but you said this is mainly street so I doubt you are going with dual quad high rise etc.
 
I've got a 400 with the 440 Source 499 kit and love it.
As a cautionary tale keep in mind the increased stroke and bore will cause a high comp ratio without any other changes.
Get the dished pistons and even with closed chamber heads you will be OK, just food for thought if pump gas is your goal.

I did have a 440 in the car 1st and was happy for the little extra room with the 400 block.
 
My plans are to use a set of ported and polished 452's. I'm planning on breaking in with 3.23's then switching out to 4.11's.
 
I did a 400/470 for my 69 B'cuda. Eagle crank, Manley 6.760(RB) rods, Diamond pistons at 10.2:1,Eddy 84cc heads,Comp cams street solid roller,Eddy RPM intake w/Holley 800 DP. I think it's a great little package for an A-body and a whole lotta fun!!
 
I haven't had either a 400 or 440, but I would go with the 400 simply because of the larger bore - gives more piston surface area.
The other benefits of a slightly more compact build and few pounds lighter make it even better.
 
Well my vote is for the good old 440...either one,440 or 400 can make 500+ hp easily without the expense of a stroker kit..but I also understand the 400/451 set-up to be a little lighter and very powerful and proven performer,I really dont understand why everyone thinks they gotta have 500+ci to make power from the bblk mopar when I've seen 1st hand a 451 indy headed non filled block[400] with 440 crank aftermarket rods run 4 yrs without a refresh and run in the mid 9's[9.48] in a 69 RR which happens to be Matt McGwirk from Seneca Mo[joplin],after having that 'little motor' he decided to go to a 511,upgraded indy heads and bigger everything,spent 'thousands',he runs alcohol and nitrous now runs 8.89 with a 3.50 9"rear,strickly a strip car...but for a cruiser on the street a 400/440 even with iron heads can be combo'd to run a street friendly hi 10's[in an a-body] without power adders,if you want more then add power adders such as nitrous,alcohol etc..but on the flip side there is no substitution for cubic inches and with the torque of mopars bblk in either form it's a winner just depends on how much money you want to throw at it....different strokes for different folks but my money would be spent on good alum heads,ported, with a 440 or a 451[400 blk] for the street....just my 2 cents
 
Packaging with the B is a little harder depending. The B is stronger and lighter (assuming it passessonic testing). Intake choices are a little fewer for the Bs and the header fitment is also worse if you go with underchassis. Otherwise - same same.
 
I did a 400/451 stroker in a 65 B-body that was one of the best combo's I ever had. Pump gas 10 to 1, Eddy heads,750 AFB on a M-1 intake. 490 lift Comp cam. Put 30,000 street miles on it. Dumped 4.10 geras in it and it ran 11.90's in full street trim @3800 lbs with driver. It is now in a 73 Cuda with another 10,000+ miles on it still going strong.Stupid for me to let that one go.
 

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440. But I also have 7 of them lying around. The 400 is the stoutest block Ma Mopar made
 
I stroked my 400 to 500 cubes. With ported 452 heads and comp hydraulic roller cam, the engine made 550 HP and 610 TQ on the dyno. So far it has gone 11.80 at 115 MPH with 3.55 gears thru the mufflers. Hood clearance is tight using the factory air cleaner. I would do the 400 again, the only thing I would change is to use the 400 rod length instead of the 440. My pistons are like hockey pucks and the oil ring is in the pin hole. Piston slap is noticeable.
 
I'm leaning towards doing the 400 stroker just to save the room. I have what I've been told is one of the best b motor intakes in the Holley Street Dominator and I have a 800 holley dp for on top. I'll probably throw a 1" or 2" spacer in there if it'll fit under the hood. The only thing I'm hung up on is selecting the cam package and rockers. Any input on this?
 
Mancini has rockers under their own label now. They're Harland Sharp bodies without the roller center setup. Nice rockers for the money. Otherwise true Harland Sharps would be the next step up for about another $250.
 
The street denominator is a great intake for the low deck big block. Shame it is no longer in production. I have one in my stash but opting for a dual plane for street use on my sock stroke 400 rebuilt with 9.5 to 1 hypers and forged 383 crank. Just a 4 speed street cruiser, not a drag car.
 
roughidle said:
I'm leaning towards doing the 400 stroker just to save the room. I have what I've been told is one of the best b motor intakes in the Holley Street Dominator and I have a 800 holley dp for on top. I'll probably throw a 1" or 2" spacer in there if it'll fit under the hood. The only thing I'm hung up on is selecting the cam package and rockers. Any input on this?
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I am running the street dominator on mine with a 750 DP. This intake is nice and low, but with a 1/2 inch thermal spacer and the stock air cleaner it was just touching the hood bracing in one spot. My cam is 236/242 duration and 544 lift. There is one larger hydraulic roller, but I figured it would be overkill for the 452 heads.
 

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The 400/451 package can't be beat. It has the best bore/stroke of all big Mopars. That being said, be sure you have the cylinders sonic tested. Only 1in5 pass the sonic test. Dished pistons are the best for the street. DO NOT mill the block for zero deck. Screws up intake bolt on. Use thin head gasket instead. This is a high revving, big torque, high horsepower package. Good luck
 
I too run a Holley Dom that I had found on E-bay.
Enough cubes that on the street the single plane is not a problem.
I also have an 850 DP on it and wish I had a bigger carb to try on it, I get the feeling it would like it in a strip setting.
 
The Street Dom is a great intake..I use an 800 DP which I think is a great street carb for these engines. Mine would no doubt eat up more carb if I was racing it but for the street the 800 has the same size throttle plates as the 750 which helps throttle response. As far as cams go...call one of the many specialists that can spec a cam for you and your application. Mine's a shelf street solid roller w/242/248@.050" and .570/.576 lift on a 110 centerline. Idles fine with a little lope,has good low end throttle response and pulls like a mother up through the rpm's
 
I did a lot of work on a 440 A body. Didn't drive it much, but lots of time under the hood. The B series is going to be just enough easier to fit everything in there. I wouldn't say anything was super hard to fix on the 440, but everything was tight. 400 would be better.
If I do another BB A body, I will do a 400 swap.

But, the 440 was pretty quick for what it was and ran strong for cheap.
 
It it's a late A body, I would go with the 440 every time. The extra .375" in stroke will net you way more power and torque than the .022" difference in bore for the 400.
 
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