Drtmod5

I recently picked up this standard bore block for next to nothing. I have heard the horror stories about these 400's, but am curious as to what others think before I possibly waste my money. This motor will be a circle track motor so filling the block won't be an option. Is it worth the time or should I stay with another 383-388 combo like I have now? Any help is appreciated.

Thanks, Dave

mytmouz

Are the aftermarket blocks available now better? Yes. Did the stock stuff work for years when the aftermarket stuff wasn't available? Yes. Personally, if I had the stock block, I would install the splayed caps and run it. I have a production block in mine now, and just got a heck of a deal on a little m crate motor that didn't live. I ain't pulling the motor out just to change the block...

hink

Before you spend any money on that block have it sonic tested first!!

DirkaDirka

I got one in my 84 Chevy 4x4 and right now I am having a hard time keeping it cool. I dont know if that is a problem with the 400s or not. I know that the one in my 4x4 has a mild cam and around 10:1 compression. I didnt build the motor or have it built so I cant tell you everything that has been done to it. I do have a set of Hooker Headers with 2 1/2" exhaust into dual flowmasters. It sounds good and runs good jsut need to figure out my overheating problem.

hammertime

The 509 casting blocks are suppose to be the best of the bunch. If its not I wouldnt use it

Tod74

I never had one iota of trouble keeping an 11 to 1 compression 406 cool on the street. Ran 180 in traffic. I've had 3 different 406's in street cars none of them ran hot. I think that is just a myth.

x2 on the 509 being the best one. That's what they say.

kwkracing

If your runing a imca class that is using a stock block, you will have no troubles, the engine will tear up of other reasons, before you should worry about the block or mains. Put a some arp studs and go racing!

jasonwfo1

i ran a 434 in a 511 block for a few years, the 400 blocks like to crack from the upper head bolt holes to the larger 1/2 inch circle water passages, i seen this in bone stock 400's,check yours, would almost bet you will find a crack.

Drtmod5

It's a 511 block #, and we run under UMP rules. Thanks for the replies.

Tod74

I thought the 511 was the 3 freeze plug 4 bolt main casting? they are the ones with the worst reputation. all mine were 4 bolt main 3 freeze plug blocks. only street motors though.