shybx1969

Has anyone raced/built up a 400 sb????Was thinking about building one instead of a 350/for bracket racing!!!!Are they any better/worse????More costly???Give it too me straight guys!!!! :twisted:

DirkaDirka

from what I was told the 400's cant hold up to the horsepower that a 350 can.

FullTimeRacing

It depends on how much power you going to make,most people will tell you to buy the SHP block and stay away from the 400

the shp block is rated to 600hp mabe alittle more.The gm block maybe 600hp,but they tend to crack

my 400 gm 2 bolt block is on the engine stand with splade main caps,hard blok to the bottom of the water pump holes,light deck job and cleaned up the cyl's to .020 to make a 404.

at frist I wanted to stroke it ,but i will be conservative with it.

littlehotrod

well i was told that a gm 509 casting 2 bolt main is better than a 511 4 bolt main..But i didnt know that a 350 block was better.

FullTimeRacing

Theres no replacement for displacement :wink:

my 2 bolt is 817 casting

OneBadGMC

2 bolt GM blocks are always typically stronger in the main webbing.

If you really want to build a good stock block, get a 2-bolt block and convert it over to a 4-bolt.

As cheap, however, as the SHP blocks are, you'd be well off to go that route.

I think I'd build a 383 (350 block, 400 crank) before I'd build a 400.

Tod74

My uncle lost TWO this season in his stock car...the first one had been ran for two years and then a big chunk broke out of the main webbing...don't know what started the destruction but when it was done the crank was broken and a part of the main cap and block were in separated from the block still with the bolt in it. It was an aftermarket crank in a 2 bolt GM block. He bought another block, had it bored .040(wouldn't clean up at .030) new rotating assembly...first night something happened..not sure what caused it but when it was over the block was split down the cylinder...And this man does know what he is doing as far as assembly goes....the class they run in doesn't allow aftermarket blocks. This is a claimer class but this engine was high compression running methanol. Dirt stock car.

supergass

If you buy the block you need and commit to the 406, you will love it. In a bracket engine they are sharp and full of torque. For the money they are my favorite engine. I built a pump gas GM block 406 with Brodix track one heads (ported) and with a solid lift cam that was 257 265 at .050 and put it in a camaro with a glide and 5000 stall and 4:30 gears and it ran 10:60s with a best of 10:55. It far exceeded my expectations!! It was a 3200lbs car with driver! They heads flowed 300 at .700 lift. on the intake. Oh......950cfm holley.

littlehotrod

well i guess its just how many RPMs u Turn them..They are people out there turns them to the max or more..When u build one and it says Up to 7,000 Rpm Dont mean u have to turn it 7,500 Rpms..I seen a few Blocks Messed up because someone turns way to many RPMs..Then they get upset and ask there self say what Happened!!!

zipper06

UH'OH, here we go again,

I've got a 509 blk. 377"in my Malibu with 5.43 gears. When i first built it i put it in an 1850 dragster, it ran 5.15 and 8.23@158mph. I pulled the chip out and it was close to 8,000 rpm. It had a (4" long crack about 3/4" below the deck) and wouldn't hold water (we ran it dry) I then pulled it out and without pulling the heads, useing nirod i tig welded up the crack and then installed it in my Malibu. It's got 50/100 passes on it and if i run the qtr. mi. i pull the chip out and let it run, most of the time around 7800 rpm. Would i recommend this heck no, but it worked for me. I also have a 511, 4 blt blk that i'm building for a prostreet truck. But truth be known, i would go with an after market blk if i could afford it, because i'm sure i'm danceing on ice.

Zip.