Should I go Big block or Small block?

What motor should I build for my duster?

  • 318

    Votes: 37 6.3%

  • 340

    Votes: 183 31.2%

  • 360

    Votes: 228 38.9%

  • 440

    Votes: 138 23.5%
  • Total voters
    586
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SpikeWills69 said:
I agree that 440 weight is exagerated. If memory serves me correctly your talking about a 100 lb diff. Put the battery in the trunk, add aluminum intake and headers and that would just about offset I think. That's what I am doing with my 69 cuda fb. I voted for the 340, but all "I" have is BB's. My 318 Duster is a different story.
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See the difference for me is that I went stock 318.....then hypo roller motor 340 and then drove my buddies 512 stroker 1970 Charger...what a difference....that's why I went 440.....8)
 
I voted 360....But stroke it to 408, put some Ported Indy heads on it with their top end package, hyd. roller cam,....good for about 580-600 horsepower.... :)
 
why 318, 340 or bb, when you have the best engine in the world: 360 !
 
I say build a 318 you can easily put it over 400hp and rev the hell out of it all day long. Also there are plenty of badass 340 360 and 440 cars try being diffeent.
 
i would go small block, but go with the 360. like they say, theres no replacement for displacement. the 340 has a good reputation for power, but the 360 would too if it came out earlier before the government choked everything down with emissions standards. i would put on a good flowing set of heads and a decent cam thats streetable, and of course all the other bolt ons that will give it more power. i would only do whats necessary with machining the block to keep costs down.
 
Let me start by saying that this weight issue, between the BB and SB, in an A body is most of time a load of crap. Sure if you take a complete Motor home 440 with it's heavy manifolds and starter and transplant it you're going to need 2" torsion bars to handle it, but very few builders go that route, hell why bother. By the time you bolt on an aluminum intake, aluminim water pump, a mini starter that weights half of the stock boat anchor, headers and fiberglass hood you've just shed 100#'s off the nose. Add aluminum heads and it's 150#'s.
The build that hasn't been talked about enough here is a stroked 400 to 452 (400 with a 440 crank). The engine bay fit is easier, you keep the power steering and brakes and you get a good handling/revving torque monster. Whether you build up a SB or BB you're stuck with cooling upgrades, good solid tranny with kit, possibley a shortened drive shaft for the 8 3/4" and discs up front if you don't already have them and subframe connectors so therefore everything not including the engine is a wash. I run manual KH factory discs and big rear drums with no stopping problems even when you got a brake happy SOB in front of ya. My biggest problem is when you plant her keeping the darling straight what with all the crap on the highway left over from winter but that's where feel comes in.8)8)
 
What are you going to be doing with the car? If it is a cruzer I would go with a 340 or 360 stroker. If racing strate line is more your thing put the BB in there.
 
Big block. I'll just copy what I've said in several other similar posts. A previous member says the B blocks are only 70 pounds heavier than a small block, and I have 95 pounds, so just subtract another 25 pounds from what I've listed. Some will say do the same to a small block, and be that much lighter, but again, we're talking about a 70 pound difference between the two motors, and lightweight B parts save more weight than they do on a small block. Small blocks, being smaller all over, have smaller bores, and less room for bigger valves and ports, which is where the power potential comes from. You can also rev lower, and be in the power band sooner, giving a longer lasting motor. Also notice that a small block 4-speed would weigh more than an automatic B motor.

I've driven a crappy handling 440 Dart, but it was slammed on the ground, /6 torsions, no sway bar, and 90/10 shocks. I've driven poor handling small block B-bodies, and decent handling 440 B-bodies. If weight's your concern, A-bodies can weigh more than some big block B-bodies. We're only talking about 100 pounds from BB to SB, and there's a lot that can weigh much more than that. Considering you can use aluminum parts on a BB, I don't think there's much to worry about. Here are some numbers:

Part....................Weight savings
aluminum heads..........58#
intake..................25#
water pump & housing....15#
headers.................25#
mini starter.............7#
Total savings:.........130#

Manual steering is 37# lighter than power, and a 727 is 75# lighter than an A-833, and who knows how much A/C weighs. Small blocks weigh the same as a slant 6, and the B motors are 95# more than that, so a manual slant 6 or small block with power steering and A/C (guess 60# for that) can weigh 200# more than a 383 or 528 A/T. Relocate the battery, and that's a 50# shift from front to back, so that small block could weigh 300# more up front than your /6 or small block pig.

Here are some real numbers from one of my cars:

'64 GT Dart, 273/904, manual steering and brakes with AC and about 1/3 tank of gas.
Without me
FL:932 FR:960
RL:698 RR:672

1892 front / 1370 rear
3262 total
58% front 42% rear

If I swapped in a big block, with the lighter parts, ditched the A/C, and moved the battery, I end up with this:

1747 front / 1420 rear
3167 total
55% front 45% rear

Less weight, and better front to rear weight ratio.
 
The 360 would be the better way to go, you could stroke it out but if you want more power go with the 440. I started out with a 383, and just now "upgraded" the a 440 stroked out to 512, tunnel ram , and solid roller cam. I'm power hungery.
 
440 with a stroker kit for over 500CI.

There is no replacement for displacement:D
 
375inStroke said:
Big block. I'll just copy what I've said in several other similar posts. A previous member says the B blocks are only 70 pounds heavier than a small block, and I have 95 pounds, so just subtract another 25 pounds from what I've listed. Some will say do the same to a small block, and be that much lighter, but again, we're talking about a 70 pound difference between the two motors, and lightweight B parts save more weight than they do on a small block. Small blocks, being smaller all over, have smaller bores, and less room for bigger valves and ports, which is where the power potential comes from. You can also rev lower, and be in the power band sooner, giving a longer lasting motor. Also notice that a small block 4-speed would weigh more than an automatic B motor.

I've driven a crappy handling 440 Dart, but it was slammed on the ground, /6 torsions, no sway bar, and 90/10 shocks. I've driven poor handling small block B-bodies, and decent handling 440 B-bodies. If weight's your concern, A-bodies can weigh more than some big block B-bodies. We're only talking about 100 pounds from BB to SB, and there's a lot that can weigh much more than that. Considering you can use aluminum parts on a BB, I don't think there's much to worry about. Here are some numbers:

Part....................Weight savings
aluminum heads..........58#
intake..................25#
water pump & housing....15#
headers.................25#
mini starter.............7#
Total savings:.........130#

Manual steering is 37# lighter than power, and a 727 is 75# lighter than an A-833, and who knows how much A/C weighs. Small blocks weigh the same as a slant 6, and the B motors are 95# more than that, so a manual slant 6 or small block with power steering and A/C (guess 60# for that) can weigh 200# more than a 383 or 528 A/T. Relocate the battery, and that's a 50# shift from front to back, so that small block could weigh 300# more up front than your /6 or small block pig.
Click to expand...

All those numbers look good but applied to a small block make it even more lighter and run a 904 even more lighter then you'll ever get a big block to be..small blocks rule!!!
 
I did comment on that in the first paragraph. We're only talking 70 pounds difference stock, and less than that when using aluminum parts on both motors. I don't think anyone would want to run a 904 with longevity in mind. Why doesn't this discussion ever come up when talking about a Charger, or another B-body? Road Runners weighed around 3400 pounds, and I see plenty of 360 Darts and Dusters weigh in over that.

As far as cool goes--I drove Darts, Chargers, and Super Bees when they were considered junk, and priced as such. I thought they were cool then, and I do now. I don't care what anyone thinks if I pop the hood and they see a big block, or I kicked their ***, and I show them a small block. We drive cool cars, and that's all there is. If a Honda's faster than me, or out-corners me, I couldn't care less. They're still driving a Honda.
 
I have or had all of the engines mentioned in an A-body. Had a 440 Duster with 1.04" torsion bars, manual steering and modified K-member. Car was a daily driver for 8 years with excellent handling. The biggest problem was controlling the heat under the hood with all iron engine including HP exhaust manifolds. a couple of installation problems include the closeness to the master cyclinder and having to dent the hood frame because of engine height.
360 engines after 73 are thin wall castings and can be over bored only .020 without sonic testing. The first 360 MP crate grenaded in about 350 driving miles. The current 360 crate is smoking excessively with less than 5000 miles, still working on the problem. Rebuilt a 74 Duster with 318 for the grand son which pwerformed flawlessly before he decided to tackle a tree and the tree won. 72 /6 Duster was excellent performer. 72 340 kicks major butt, well balanced and will walk all over the 360 POS. The 383 in a 68 barracuda is a long time project car. All of this gibbersh is to say build the 340 for the most bang for the buck. Leave the 440 for another size car application. For any application up to 345HP a small block is fine more HP a low deck BB should be used.
 
No doubt that there's plenty of power available with a small block. I'm just saying the weight thing's exaggerated. You have a point about the HP manifold to master cylinder proximity issue. Low block's the way to go with a stroker.
 
ALL OF THEM!!! lol jk

sell off some of what you have, get a 400 block and cut the 440 crank or get a stroker kit, more power than the 440 with better fit and in a lighter package, what's not to love? Or a 420hp 360 is a relatively easy thing to do and that's plenty of hp for some pretty dandy street car ET's IMO
 
360, definitely, small block size and weight with decent power, or great power if you decide to stroke it!
 
I really was impressed with the iron headed 365 I had. But I will try a 500ci B this time!!!!!!!! Did have some head gasket issues with SB!
 
you can make just as much power as a big block and still have the weight savings gains. i did a 408 for my stroker.
 
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