Small block to big block?

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J

Jamie LeBlanc

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Apologize if this has been beat to death in other threads.

I have a 69 340 Dart now. Wonderful car my dad bought in 1985. Sat in the garage for almost 30 years and then we got in on the road. Was an original slant 6 but my dad got a 340 and the 8-3/4” out of a duster in the 80s.
I’m his son and I have the car now. Absolutely love the look the of the car. Currently doing a disc brake swap in the front and switching to BBP for the front and rear.
Over the winter I want to address the motor. Like the 340 but it just doesn’t have the enough of the wow factor for me. It’s got x heads I know that much about it.
I’m debating stroking the 340 to 416 CI or maybe the Hughes 435” kit …
Also an option to build stroke a 400 block to 512” as I have that as well.
I realize with the big block it would require the new trans, rad etc…

I don’t mean to sound pretentious but money is not a huge factor within reason as long as it’s not more than like 40k.
Basically I want something I can cruise around in at generally low rpm and have some major torque. Street car primarily that I may bring to the strip the very odd time. I’d like to hear some real work opinions on some people that have done a similar swap. Is a properly built small block even comparable to a kick *** big block???

My dad sold one of his former cars that had a 454 chev motor and I miss that Low end torque feeling

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i'd say with what you're looking for a stroked big block will scratch that itch. absolute gobs of low end torque and no drama. you could probably build something real stout that could put down 500+ fl/lb and be done by 5200rpm

while a stroked small bock is certainly no slouch and will absolutely be balls hot, the driving experience is just totally different.

if you can, see if you can catch a ride in each flavor and that should pretty much make up your mind.

the low deck 383/400 is a little bit easier install. you'll obviously need the usual: swap mounts, headers, the transmission, maybe an upgrade to the cooling system. but also a consideration toward stiffening up the frame-- subframe connectors, torque boxes-- and bigger/better brakes cuz it's always nice to have a bunch of woah to match all that go.
 
Is the 340 tired? if so rebuild it.
440 torque is fun, but with fuel costs, my poor *** would be sticking with 16mpg, instead of 8.:lol:
 
Go big. You may or may not need a new radiator as both big and small blocks have the option of WP inlet on either side. BUT, the radiator may not be up to cooling your new engine. We have a factory 340 car and have built a couple of 440 cars. I don't build anything with huge cams, etc. The difference between the 340 and 440 is tremendous. There's just really no comparison on the street even if there isn't a huge difference in quarter mile times. As for fuel mileage, not much difference there, either.
 
Jim Lusk said:
Go big. You may or may not need a new radiator as both big and small blocks have the option of WP inlet on either side. BUT, the radiator may not be up to cooling your new engine. We have a factory 340 car and have built a couple of 440 cars. I don't build anything with huge cams, etc. The difference between the 340 and 440 is tremendous. There's just really no comparison on the street even if there isn't a huge difference in quarter mile times. As for fuel mileage, not much difference there, either.
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Awesome that’s the kind of real world info I appreciate. I really wouldn’t have questioned it much until I drove my dad’s big block Chevy car. It’s a massive heavy car but it felt so much better down Low in the rpm even though if we raced I’m not sure that he would actually go faster over a 1/4 mile. It was a fairly mild build about 525 hp and similar torque.
 
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