400 SBC vs 454 BBC

[BigBlackChevy77]

Hey guys so I'm having a debate between myself and all my friends. I currently have a 400 SBC and a 454 BBC bare blocks just sitting in the garage. Now one is getting built for the k10 but I don't know which one I should toss in. The 400 is lighter and more compact and still makes decent torque from what I hear ( can't find ANY stock numbers for HP/TQ ), but the 454 is much more powerful in stock form due to being much larger. Both are 2 bolt main, 454 is a 289 hi performance cast and 400 is an average 817 casting. My truck will mostly be seeing fields, trails, forests and lots of mud. I plan on eventually running 40" tires with one tons with 5.38 gears. I have a sm465 so I know it will live up to the 454 I just don't know how long if put better heads and a cam on it. Any input would help !

 

[shiftpro]

You want to run 40s...! Right on 454 ALL THE WAY. You will need decent heads like 781s. Large oval ports, stay away from square ports as they like rpms.
The 400s have always been a precarious block, as the siamese cylinder blocks tend to have ring sealing issues which when worked hard,
towing for example, get out of round.
BBC makes lots of heat too so if you upgrade to this you will need more rad.

 

[BigBlackChevy77]

You want to run 40s...! Right on 454 ALL THE WAY. You will need decent heads like 781s. Large oval ports, stay away from square ports as they like rpms.
The 400s have always been a precarious block, as the siamese cylinder blocks tend to have ring sealing issues which when worked hard,
towing for example, get out of round.
BBC makes lots of heat too so if you upgrade to this you will need more rad.

How would the sm465 hold up behind a mild bbc ? I know its somewhat factory rated at that 465 lb ft number.

 

[shiftpro]

Lots of guys run these transmission and beat them all day with big cubes. Don't skimp on the clutch... and no worries...

 

[BigBlackChevy77]

Lots of guys run these transmission and beat them all day with big cubes. Don't skimp on the clutch... and no worries...

Gotcha well thanks sir. Sounds like I'll hold on to the 400 for something else

 

[Paladin]

454 and don't look back! Only thing behind you are the folks you've passed!

 

[77 K20]

Depends on how much money you have. Parts for big blocks are big bucks. And for offroading sometimes the weight of a big block isn't a good thing. And what type of front bumper are you going to run? A heavy duty one with a winch? Then there is even more weight. Ya gonna sink.

Just some thoughts.

 

[BigBlackChevy77]

Depends on how much money you have. Parts for big blocks are big bucks. And for offroading sometimes the weight of a big block isn't a good thing. And what type of front bumper are you going to run? A heavy duty one with a winch? Then there is even more weight. Ya gonna sink.

Just some thoughts.

Good point that's why i was thinking 400 at first because I want a winch bumper upfront and that's a lot more weight in the front end. But maybe the 454's extra hp and torque will help offset that ?

 

[77 K20]

You will just have to make sure you select your front springs to support that much weight. So something like the Tuff Country HD springs instead of the softrides. And with a big block and a winch then maybe your springs will sag/settle more than a small block.

With more HP/torque then you might start breaking other parts though too... not trying to rain on your parade but just something to think about. Driveshafts? Front axle? They have already mentioned having a strong clutch.

I've had 3 400 engines. I really liked 2 of them and the 3rd one had issues. Maybe throw that 400 crank into a 350 block...

 

[Handy Andy]

how bout a 377 stroker? 400 block with a 350 crank... if your gonna be doing lots of mudding, and with the gears you plan on running, a 377 stroker built to handle high rpms sounds like a decent option. The biggest deterrent for a 377 stroker is that in order for it to be really worth it you gotta spend some dough and buy some good internals.

I've always wanted to build one, and some day I may if I ever get around to building a dragster.

 

[shiftpro]

Good point that's why i was thinking 400 at first because I want a winch bumper upfront and that's a lot more weight in the front end. But maybe the 454's extra hp and torque will help offset that ?

You might want to consider mounting your winch on a hitch receiver platform and keep it behind the cab. Build a front bumper with a receiver as well as rear bumper with receiver. Mount a receiver to a plate you can bolt down in the box, with a lock. Run synthetic cable so you can actually pick the bitch up. This keeps the weight off the front end, and the winch out of the public's eye. Most of the time we need a pull backwards to get us out of the hell hole we drove into.

 

[BigBlackChevy77]

You might want to consider mounting your winch on a hitch receiver platform and keep it behind the cab. Build a front bumper with a receiver as well as rear bumper with receiver. Mount a receiver to a plate you can bolt down in the box, with a lock. Run synthetic cable so you can actually pick the bitch up. This keeps the weight off the front end, and the winch out of the public's eye. Most of the time we need a pull backwards to get us out of the hell hole we drove into.

Holy **** that's a good idea. I know an old man in my buddies neighborhood that did that but he set it up wrong and I never liked the idea too much after that, but i do like the point of just swapping it around as needed would make life easier. I'll have to look into that

 

[77 K20]

I had read this a few days ago:
http://www.fourwheeler.com/how-to/b...oking-at-winching-from-a-different-direction/

Very appropriate and it even shows a squarebody.

You must be registered for see images

 

[trukman1]

I've had both. I'd run the 400 till it croaked (don't count on it ever going bad though) while building the 454 as I got the money so it wouldn't be a financial hardship. Don't underestimate the 400! It's a torque monster for being a small block. I heard all the nay sayers on the 400 but mine was super reliable and performed excellently. Regretted selling it for the 454 until I built the BB with a 268H cam from Comp Cams and had my Q-jet rebuilt by National Carbs.

 

[4WDKC]

Which can you afford?

I have 2k in my 406 short block and porting heads I already had. big block wont be cheaper unless you risk throwing used parts through the block.