To big block, or not to big block, that is the question....

[DrEamer]

Sorry for the Shakespeare quote adaptation, but it was sort of funny to me. Anyway, as I progress on my Challenger build, I am mulling over which engine to go with. My first choice was to to go with a 470 stroker in part because my car came with a rebuilt big block 727. So I did not want to waste it. Then again, I do not know who built the 727, or what kind of specs it is built to. Most likely have to have someone open to it up to see what I have, adding the cost. The other reason for wanting the 470 was it seemed like a cool combination with a lot of power. That said, the 470 probably is way more engine than I need. My plans are for more of a cruiser than a race car.

My other thought is a 408/410 stroker. Part of it is sentimental, since my first two Challengers were small block cars, with one of them being a A-66 package. I like the torque curve with the the 408 with some of the combinations peak figures being the 500-535 ft/lb range. That's enough to have fun without being overkill. One of the other benefits is lighter weight without the need for aluminum engine parts. The final kicker is I can get a 408 crate or short block from a reputable builder for less money then what I can build a 470 for. That factor alone may be what is making me think more seriously about it then before.

So, with all this in mind, I am looking for the pros and cons of each engine choice from those that have ran either of these engines. I'm still kicking ideas around, but just want to get a little bit of input and guidance before I start to collect parts.

 

[DetMatt1]

Sounds like the small block would be the way to go. Do you have a small block trans yet?

 

[340challconvert]

I personally always liked the small blocks
Stroked, they provide plenty of power and torque
They handle better with less stress on the front end. (more fun with induced torque steer in the corners)
It also seems you have a cost advantage with the small block.
As Matt mentioned; you would need a small block 727. (you could always covert to a 4 speed!)
Good luck w your choice.

 

[rklein71]

I decided to go with a small block for a lot of the reasons you said. Here is my 408 in my 71 Barracuda. I have not driven it yet, so I can't speak to the power output, although I am hopeful that it will have good power.

 

[FLY'NFISH]

I have been very pleased with my 408 crate engine. The combination including my original refreshened 904 with a tru-trac 3.73 rear has made it a beast of a street car. These are fun things to decide on!

 

[henry b]

I say go big block mild stroker 470 b block to 512 rb block is the way to go cost factor isn't much different building a a motor or b motor and b motor will make more HP & torque for less then a small block + you all ready have the trans. to me its a no brainer. heck I'm putting a strocker 528 rb motor in my 69 Plymouth valiant.

 

[70Barracuda]

Im with Henry, you can use stock rockers and a small cam make great power and torque. Aluminum heads and water pump put it in the SB weight range.

 

[rbbruno3]

I find this kind of funny , those who have big blocks say go big those who have small block say small. So I guess it’s a win win which ever way you decide to go.

Just remember there’s no replacement for displacement LOL

 

[fk5aar]

I have to go small block....going in aar and almost done, good luck with yours!

 

[704406]

I've owned both 440's and 340's E bodies all in stock form. For handling you can't beat a 340 E body with a rear sway bar.
I've not had the opportunity to try a 408 small block, or a 470 or bigger big block, but I agree with rbbruno3 there is no replacement for displacement!
It depends on what you want, you are doing this for yourself, choose one or the other and then enjoy it!

 

[Chryco Psycho]

50/50
First, I love a number of things about the big block , Air gap intake , no water in intake , dist in front easy to access , water pump is replacable without removing the whole housing , deep skirt block , cross bolt mains , flat oil pan sealing surface , oil pump outside not in the pan , good oiling design .
I have always wondered why the small block was not designed with a lot of the same features / advantages .
The small blocks are great too , much lighter , very rigid , tall deck allowing a lot of room to stroke them .
Later 87-92 blocks are set up for roller cams , the best factory heads are the same year 308 casting not the X or J .
Some great heads are available , W2 are killer but expensive , 6 bolt blocks such as the R 8 using W7,8,9 heads are serious power producers , if you are running headers make sure you use TTI , Dougs or Hooker 5115 that stay above the steering center link , any that go below get hammered flat quick . For higher rpm oiling mods are generally required with a small block tho .
I would never build a 383 , to heavy with similar stroke to the 318 so not a lot of TQ either , but building any stroker is awesome , over 400 ci in a light small block is great , if you are going big block 451 ci + is almost mandatory , A stroked 412 small block with Tq is a great combo compared to a 413 big block . Any stroker will rev fast , a 400 /451 for example will remove 7 lbs of rotating mass mostly from the pistons & crank .
There are very valid reason to build either & you get to choose !

 

[DetMatt1]

Well it looks like we’ve officially not helped him...

 

[DrEamer]

I'm not sure how much "Help" that I have received, but if nothing else, it has been a fun discussion. I have put in a lot of time figuring out a 470, so now I am looking at the 408. The 408 of interest is either a late LA or Magnum based stroker. The main draw for these are both factory hydraulic roller engines, which I want regardless of size. Thanks for all those who took time to replay!!!

 

[Fire24]

I know I am just a new guy here but I have had both engines currently a hemi in a cuda but I recently sold my 70 B-body with the 408. That 408 would walk all over the hemi and quite frankly I wish I had never sold it. It was one of the best running snappiest cars I have had.

 

[mrjlr]

I vote small block. .....the power of a big block but much lighter.
My Barracuda "could" hold a big block but ugh....what a PITA that is.....

I'm going to stroke my 318 to 392

Jeff

 

[DrEamer]

I thought that I would just do a little update since it's been awhile I posted my question. I have decided to go with (drum roll please).... a small block. My choice is based on a lot things all ready posted, but in my case, I think I made the decision for how I am going to use the car. Thanks everyone for the input.

 

[burntorange70]

Right on. That's all you can do is weight the options and go with what is best for you. Either way you can't go wrong and your going to have fun.