You can expect a little better numbers. Not too familiar with the 400 block and what you can do to it, but my engine builder actually runs a 377 which is a 400 block with a 3.48 crank. He says he loves it, a real screamer.

 

u think 500rwhp is possible with a 400 block.....i found this one for cheap....

http://competitionproducts.com/prodi...umber=BLK400B6

 

Like I said I don't know a lot about the 400 block. The only way to do anything bigger would be to get a 3.875 or 4 inch crank and I don't know what if any problems there would be. 4.185x4.0 would be 440 and .030 over would be 445. At the least you could run a 413 with stoke stroke. All of which would make more power, but you would need some serious heads to get there. You would defintely be closer with a stroked 400 if it's possible.

Edit: Did a little checking and you can get a 4.0 stroke crank for use with a 6.0 rod if you wanted to make a big cube small block.

 

http://competitionproducts.com/prodi...er=10710040PK3

will these heads cut it?

4.185-3.875......whats that bore and stroke come out to be?

 

You aren't going to get there with cast iron heads. Can't run enough compression.

426 and 432 .030 over

 

If you like Dart then go for the Pro1 230's and get them ported. You can also run a Brodix Track 1 head. If you don't have anything to start with you can even get a 15, 16, or 18 degree head.

 

its not that a like dart its just they have huge intake runners and big valves. i thought that would be a good thing. i saw a 72 Nova in a mag running a forged 383 with tha same heads and a 250 shot of n2o runnin 9's. and i dont want tha compression to be that high because its also goin to be a daily driver. im goin for about 10.1!!!!!

 

Maybe someone else can chime in here, but compression and pump gas is relative to a few things. 10:1 on cast iron heads I don't think will work out too well. I could be wrong, but I had an Olds 403 and I remember trying to keep it under 9.5, closer to 9. I understand there are other things like DCR to consider, but I thought that just the cast iron itself was a problem with holding in the heat causing it to be more prone to detonation. Maybe someone will chime in who knows for sure.

 

10.1 SCR or DCR??

I would shop ebay for a set of decent heads or racing junk. You can get some real nice heads for cheap if you shop around.

I would stay away from a factory 400 block. If you notice all the big inch SBC's are built on an aftermarket block, and for good reason. The factory 400 blocks are just a crack waiting to happen.

You can also tap you heads for reverse cooling and run a little higher compression as long as the cam is right. I think you could get away with ~12.5: SCR as long as the DCR comes in at or below 9.0:1 with aluminum heads.

 

umm, well an aftermarket 400 block runs in tha thousands so back to tha 383.i will be happy with 450rwhp. i think thats possible. i remember Hot Rod mag. did a buget 383 and it made like 520fwhp. im sure with a lil bigger cam and better heads than they used i can push it up to 560flhp. i think that would get 450rwhp. what do yall think?

 

So that's what you should probably do. Find a magazine article where they built a killer mouse motor and just copy it.

As far as heads are concerned:

http://competitionproducts.com/prodi...er=11720040PK3

The price difference over those Iron Eagles is negligible compared to the power potential.

 

are tha alumium heads that much better?

 

It's not even so much that aluminum heads are better (I think there is a lot of arguing on that subject) it's that those heads are so much better than the Iron Eagles.

The heads are where your power is at. With the right set of heads (matched to the right cam of course) any engine can make good power. And for the most part there are only 2 ways to make big power with a naturally aspirated engine; displacement, and RPM. You can turn the thing to 8000+ rpm to make the power you want, or you can just build a 434. Either way you choose to do it, make sure you put a set of heads on the motor that will be able to feed those power levels.

That's just my opinion, I'm sure someone with a greater level of experience can help you more.