I know of a 400 SB for sale, its fully machined except it needs the finish hone. I was originally going to buy one for my buildup but NO ONE around here has them because all the roundy round boys bought them up!!! Its a 2 bolt, .040 over and the guy wants $350 for it. If he still has it i bet he will take $300, my question is.... how much hell can a 400 block really take. If i get this thing its probably going to be built around my RR200's, so id probably have a 6,500 RPM max. I wouldnt be racing every weekend but it would be necessary to have this thing running 10's or i wouldnt waste my money. What do you all think? The price is right, but the "400 gremlins" have me thinking alot more than twice.
The short block would probably stay 2 bolt and be studded, possibly girdled. Cast steel scat crank, my 6" eagle H-beam rods and big dish SRP pistons for 10.5:1 comp with 60cc heads.
Top end would probably be an RPM manifold, Maybe a motown, cam would probably be 24X's/25X's @ .050 lift in the high 500's on a 106, keep my 1 7/8" headers and 750 mighty demon, I think it would be an ass kicker with my Richmond 5 speed and some 3.55's Im just thinking, hell maybe i should buy it for the 70 Chevelle i dont know, its all just a thought.

i'm not sure how you are gojng to run 10's with those parts, unless it's a vega or something very light. with those parts it shouldn't be a problem for a 400 to hold up nicely in that rpm range, IMO.

yeah its just a thought on parts, honestly id probably end up with some 210-220cc heads and a super victor intake, my Nova weights 3260.

with a .040 over bore, I would have it sonic checked for sure. .040 is about the max for a safe overbore on a 400. The thrust side of the cylinders get notoriously thin.

those headers will still be too big.

Nickel333
For that price pick up the 400 block no matter what you want to do in the future, that is a good price, and they are getting rare.
My 406 2 bolt already has Brodix RR 200 heads and my current cam is 236/236 at.050 solid roller lift with 1.6 is .585. I drive a stockish 68 Nova with Tremec TKO-600 5 speed, 373 rear on 275 40 17 BFG G-Force KDW tires.
In the next month will swap the cam for an Isky 244/250 @.050 SRoller lift a tad over .600. I am aiming for low 11's, the weight of the car is 3190. Mine has an RPM air Gap, and 750 Demon DP. Eagle forged rotating, Probe ultra light pistons hung on 5.7 H-Beams. Compression is low at 10:2, but the 406 makes so much low rpm TQ with the current cam I have fits holding 2nd gear with 10.9" BFG wide tires. The larger cam will help move my TQ curve up a bit in the RPM range.
Once the cam is in, a rear wheel dyno, and A/F tune will give me a better idea if I have to shed a little weight to get close to 11.00.
I am not into competitive racing, but plan a test and tune with BFG 275 40 17 DOT drag radials just to see what it will do.
I will be posting my dyno results once we have them. So hang on to those RaceRites, and if you don't see my post, email me on my personal mail mid January.
If I can make 440 at the wheels, I just may have a shot at the 10's, cause the 406 with those Brodix RR heads does make an bucket load of TQ.
Your 350 struggles to get 3200lbs to 11.88's, cause its lacking TQ. The 406 will give you the extra TQ you need. My rev chip is currently at 6,600, but with the new cam, I may have to change it upward, but the chassis dyno will confirm where my new power curve is.

If I ran an 950 DP a Vic Jr a solid roller in the 260/270 @.050, 10's are mine. BUT this is almost a daily driver, and a show car as well.

There is always ifs involved in makin power.

The car is a show and go ( Four 1st place trophies this year) that gets about 6,000 miles a year on it, so I have to keep it somewhat tame for all the street miles.

HI Nick,
I certainly don't feel the 10's in your car is all that far fetched with a 400.
You are only talking about 500HP which should not be a problem with a 400 with your heads.
500HP at 3250lbs should easily put you about 125 MPH & the 10's of course are up to you after that but the power would certainly be there.
I would prefer splayed caps but the 400 is very capable of 500HP with just studs at the RPM's your are wanting & in stock form I would prefer the 2 bolt block.
It does not have the same problems as a 2 bolt 350 block regarding the caps moving as you have more clamping area. The registers are the same for a 2 or 4 bolt block & if you stud it & don't detonate it, it will handle 500HP no problem as long as you keep the RPM within reason.
As far as .040 over, it is the max I prefer to use. I have sonic checked a number of the 400's & most are reasonably thick but it is a good idea to check it before spending money on it.
I would love .200 or better but this is real life so,,,,, :D

Here is part of an old post on cyl wall thickness:
I agree but just want to add the .160 minimum is what you want from about the center of the cylinder up on the thrust side.
You will find the cylinders get a lot thinner at the lower part on a lot of blocks & this is not a problem. It would be nice to see .160 everywhere but it will be a pretty rare block that is this thick down low.
I have seen a lot of 400's in the low .100 to as thin as .080 at the bottom of the bores.
Again, I don't feel this is a problem, built a lot of them & they are still fine.
Of course if you can get a Dart block or the Bow Tie Sportsman block, they have real cylinder walls ;)

As for the headers, gotta agree,I think it would be faster with 1 3/4" :D
You just don't need that much header for a 500HP 6500 RPM engine.

Hi Pat, graemlins/waving.gif

I know about the headers guys, but its what i have and i got them dirt cheap. Id love to trade for a 1 3/4" set but i cant find any takers who are making the kind of power 1 7/8" will require. {probably over 600 hp or so id think} Any traders out there? Theyd actually be getting a 50 dollar deal cause these headers are 50 bucks more than the 1 3/4".
And the reason my motor dosent make any torque is because im WAY over cammed, coupled with my headers. Im taking care of the cam this winter. And im going to get low 11's out of this damned 350 come hell or high water.
Mind you my ET was falling on my first 3 runs just on me improving my driving and expierementing with launch and shift RPM's, then i ran that 11.88 and my 3rd member let go on the line the next run. Im 100% sure this motor has more in it with tuning. OH and i found out my lash was extremely loose!! Im talking .015 loose!!!

Nick, make that 350 run! Sh!t can the 1-7/8" headers, or put them in the basement for another project, give them to your best friend, turn them into modern art, whatever, just change them to 1-5/8" headers. 1-5/8" is the largest you need on that 350!

the lash being that loose, although outside the design parameters of the lobes, was probably a good thing, as it shrinks the effective duration of the cam. In your case, having a cam to big to begin with.

Reguardless, you're doing fine, and IMO 11.80's is very respectable from a mis-matched combo and a stick, with only a few passes to work on your procedure!
Not bad at all!

Just fine tune the engine combo, with a much smaller cam on a tight LSA, smaller headers, ect. You're going in the right direction, just dont get caught up in the "bigger is better" again. I see you were thinking about a super vic intake, which is WAYYYY to big for that motor.

200cc heads are fine, ported out to 210 is the most you want. Afterall the BSE small block, in its current form with 11.5:1 compression and a 252/260 dur. cam is going 10.70's is decent air weighing in at 3100lbs! and Still only 355"

Sorry to be brief, but i'm busy today, if want me to advise specifics on what i think you should do, email me at SpeedyGoomba@yahoo.com, and we'll go over the combo and what i think you should do.

Brian

I hate to admit it but I agree with Brian more less . . . just swap in a smaller cam and see what it runs in the spring.

Better yet, take that money you want to put into a used up 400 shortblock and just put a 248/254* 108* LSA roller in it and leave the rest alone . . . you'd need about a grand for springs, lifters, the cam, and all the other odds and ends.

There ain't much left in a +.040 400 block