Chevy 400 block

[latemodelracer45]

Wanting to build a 2 barrel engine using a stock SBC 400 block. Thinking about a 377 or 400 cubic inch motor. I have done a lot of reading and hardly no one recommends these blocks? Everything says use an aftermarket block. I understand the 509, two bolt main block appears to be the preferred one to use if you use one. If the machine shop says the block checks out ok, at approximately 500 hp and 6500 rpm, will one of stock blocks be ok?Thanks for any info!

[SLM98]

I would only use a 511 block four bolt or two bolt. Nothing else will sonic even close to what you need for wall thickness. Dont know where the 509 became the prefered block. There is a light and heavy 509 block, can identify by the boss on the passenger deck. The light is about 1 1/2 inches wide the heavy is about 3 1/2

[dereksehi]

We have always used the 509 block two bolt and put splayed steel caps on the center three mains and steel strap across the rear main with arp studs and haven't had any issues. Also we plugged the steam holes in the block and put deck plugs in. With a two barrel I wouldn't be too concerned about the stock block. As far as engine size with the two barrel I would go with a 406 instead of a 377 because they are a top end engine and like to be twisted that's not going to work to well with a two barrel.

[CNC BLOCKS]

400 blocks are always a crap shoot I have seen them crack just bolting on a torque plate making the block junk.

On 400 blocks I get 100% up front.

Buy the time you spend money on clean and mag, sonic test, splayed caps and machine work to put the splayed caps on, decking, bore and plate hone and in most cases I have seen dealing with an OEM blocks the lifter bores need to be corrected.

Get a Dart SHP or SHP PRO block and don't look back.

I have seen to many guys waste good money on a 400 block.