400 Block worth.. ??

[SpeedAddict02]

looking through Craigslist.. Guy has a 400 block.. .040 over.. doesn't list casting #. Ya know what, I'll just link it..

http://longisland.craigslist.org/pts/3176940189.html

This thing worth $225?? Looks like it would need to be tanked again and gone through b/c of the surface rust..

I love the 400 motors.. (yeah, little biased ) And would love to pick up a good block and build one again.. But I dunno.. seems like a lot for a bare block.. I would think $100 absolute max I would shell out for that..

what do you think?

 

[Gary S]

I'd have a hard time spending that much on a bare block. It is a 2 bolt block, and going from memory, the only 4 bolt blocks were 1970. The rest are just 400 blocks.

A few years ago, my Son bought a 1978 4x4 pickup for $500. The pickup had a 400. He drove the pickup another 10 or so years until it got so bad he parted it out. He saved the 400 engine, and sold enough other parts off the truck to get his $500 back. He likely will never use the 400, but he has one if and when he needs one. The moral here is that 400s aren't that rare or valuable.

 

[my24ktrat]

...I sold a less desirable 400 4 bolt main block a while back and got $250 for it , sold a 2 bolt main longblock for $475 , it needed to be rebuilt, had it listed for $550 ,got ALOT of calls on both. They are harder to find than you think, decent . I'd say 200 bucks for a virgin block is good , maybe depends on the area , just my.02, DC

 

[79RedZ]

Sold a 79 400 short block a year ago for $250. Sold it as is, could have been cracked for all I know. 400's are hard to find around here.

 

[david.rosol]

Unlike all the other small blocks, two bolt mains are stronger for the Chevy 400 small blocks... and more desireable, too... but from the pic, looks like a lot of rust for it to be ready to build... I would make sure it could be cleaned up and not pitted, maybe have it re-honed maybe, and proof it's been checked over for cracks and all before I'd buy it... otherwise, a 400 makes a pretty torqee motor and that's seems to be a good price.

 

[NorCal_71]

That 400 block has 3 freeze plugs per side,
I believe the more desireable 509 blocks only have 2 per side which gives them more strength.

 

[kik_start]

if I had to do it again, I would just get a dart block....
To make the stock 400 blocks worth anything they need a bunch of work and you still just have a stock block.

 

[1971SS]

I wouldn't touch a used .040 over 400 block...

 

[79406RS]

I wouldn't touch a used .040 over 400 block...

Exactly! Get a complete, standard bore 400 2bm. Then, if it can pass the machine shop challange, build it.

 

[Rich Schmidt]

I wouldnt worry about it being .040 over. I have a .040 over 2 bolt in Frankie,making over 400 hp without any issues. I swear by the fact that 1976 and later 400's(came in vans) were made out of softer metal and are the ones that crack from the head bolts and the bore. I have seen them do it,but not any of the earlier "orange" 400's. I also never had a problem with 4 bolt caps,I think that rumor is BS unless it was discovered by somebody trying to make 4 digit power out of a stock 400.

I paid $225 for the 400 that is in Frankie,it was already done fresh .040,but it was clean and rust free. I would make sure that engine can be made ready to run with just a clean up.

As for the bore size,I have never had a problem with the bores themselves,as a matter of fact I think the bores on the 400 are supported very well because they are siamiesed. The real issue with bores is how thin the area between cyinders get. It funny that just .060" removed btween 2 cylinders makes the space look super thin. Head gasket retention with nitrous or blowers has been a battle for me,and there isnt much room for O-rings. The decks are fairly thick but the amount of deck space just makes it impractical to seal. Using good heads with thick decks really helps a lot. Stock GM heads are pretty flimisy in the deck surface compared to just about any iron or aluminum aftermarket heads.

Another plus of the factory 400 compared to a factory 350 is that even with 2 bolt mains the block is stronger then a 2 bolt 350. The larger main size of the 400 required that they move the cap register all the way out to the pan rail like on big blocks,so the caps really stay in place better. The 400 main diameter offers a little bit more jounal overlap the the 350 mains which means a stock 400 crank is stronger then a stock cast 350 crank.

If the block can clean up without further boring,isnt a 76 or later block,and your intentions are a nice 500hp or less engine then it is well worth the money.