How can I identify a chevy 400 small block in the truck. Heres a pic of my blazer that is suppose to have a 400 in it, but I am being told with the passenger side dipstick its a 350?

 

The 400 has 3 freeze plugs all the other sbc only have 2...

 

some 400 have 2 freeze plugs also.. i have one

 

Could be a 383, but i've never seen a 400 with a pass side dipstick, 400's are all left. That is a later modle block you have there 79 up 305~350. Easiest way to spot a 400 is the balancer will have a cut out, not smooth like the internal balamced 283~350's, also the block will have ribs down by the freeze plugs where the 350 is smooth. 400's don't have the 1/8'' pipe plug above the timing cover like the 350's it's just a undrilled boss. The last 3 casting numbers on the back of the block are 511, 509, 817.

 

I still think there is a cast mark for it only it wasn't done.. Check by number 1 cylinder for a buldge in the block, (iirc) they call it a steam pocket.. whast the cast numbers on it>>>????

 

I still think there is a cast mark for it only it wasn't done.. Check by number 1 cylinder for a buldge in the block, (iirc) they call it a steam pocket.. whast the cast numbers on it>>>????

Stock48, wasn't some 400 internally balanced?? I remember reading that some where..

 

your right john. there is a cast mark for one http://cgi.ebay.com/ebaymotors/ws/eB...m=330364226915

 

cant find the casting numbers on the back of the block. I know it originally had a 400 going by the vin# but that doesn't mean it hasn't been swapped.

 

the casting number is on the drivers side behind the head.. your prolly gonna have to scrap some dirt and sludge off to find it..im pretty sure its a 350.. i never knew of any 400 that had the dipstick on the passenger side

 

I mean it's not a big deal if it's not a 400 and is a 350, I would just like to know. At least my cam will still work with it.