anyone run a 400 small block?

[WantedaDodge]

Does anyone here run a 400 small block? I'd like to have 300 horsepower and 400 ft lbs of torque on 87 octane before I try putting 35's on my truck. I could cam my current 350, but I don't think a cam, intake, carb and headers is gonna get me there from a stock '84 350. The motor runs great, I know Edelbrocks performer pack with there fuel injection will make about 350 hp on 87, but that's like $3000 just in bolt on stuff. I don't wanna go there.

I was wondering if maybe I should just build a 400 or maybe do a 383 stroker. I kinda hate to tear into my 350 since it runs so well, but hey, big deal, gotta make the ponys. I want something that will make the power, get decent fuel economy and run on 87 octane. Also, keeping it under 5,000 RPM would be good.

Any suggestions?

 

[pauly383]

I'd get rid of those 3.08's first .

I noticed a remarkable improvement just going to 3.73 from 3.08 ( cheap ) . I'd rather have 4.10's or 4.56's

 

[WantedaDodge]

I have a D44 and 14 bolt with 4.10s ready to go in. But I know it's still gonna be doggy!

 

[sweetk30]

loved my built 400 sbc. lots of bottom end power. just need good cooling system.

 

[MattK]

koldsimer is runnin a 400. that coupled with the sm465, he's got plenty of grunt down low.

 

[GM Man]

Got a 400 in my 78 Jimmy. Previous owner went through the block with all of the upgrades, and it can light up the tires with 2.76 gears..

 

[keifer]

Sounds like your current 350 has smog type heads. If you put a decent set of heads(vortec) on your 350, then install a cam, intake, headers, you can make 300 hp easy.

 

[ntsqd]

There's some tricks to making the 400 block cool better. Try searching some of the street car forums about it.

Personally I think a 3.75 stroke in the 350 block is the better option. The flame speed of gasoline is fixed, so the bigger the bore the more stroke you need to get max efficiency out of the engine. Or you have to bring the max RPM's down. When crawling this probably isn't that important. It's the drive to the trail where this could be important.

I think a 4" bore is about as big as it can get b4 the efficiency (read mileage) starts falling off. This is the reason Yuropeon performance engines tend to have a lot of small diameter bores. There are tricks that can be done with bigger bores to improve their efficiency, but I suspect that if you applied those same tricks to a smaller bore that it would work that much better than the bigger bore with the same applied tricks.

 

[K30CJ]

I've had 400's and loved 'em. Even built a 434 stroker when I used to mud drag. Just have a good cooling system and keep the rpm's down. I plan to replace the block in my Jeep (TBI 350) with a 400 whenever it dies and keep the injection system. Don't let anyone scare you away with old wive's tales.

 

[MNorby]

I ran a 400sbc with a stock rebuild fow a while. Turned my 40s with 4.11 and 4.56s really well. It didn't like swimming though and spun a rod bearing. I could have fixed by I put the 454 in then