Murphy Posted December 18, 2014 Share Posted December 18, 2014 I have an interest to eventually got with a bigger motor and have been occasionally searching for 400 sbc's. What I don't understand is why several CL listing that I've found, state a 509 block with 2 bolt mains and then they show this picture. Sure looks like 4 bolts to me??? Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted December 19, 2014 Share Posted December 19, 2014 I'd like to see a bigger picture, those look like after market main caps Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted December 19, 2014 Share Posted December 19, 2014 I aggree with Sam on the aftermarket, heres what the bone stock ones look like on my 71 sb400 Quote Link to comment Share on other sites More sharing options...
Murphy Posted December 19, 2014 Author Share Posted December 19, 2014 That particular photo stated .030 over bore in the ad.........so apparently splayed center caps/bolts have been added as it was originally a 2-bolt? Just needed to verify that I'm not misunderstanding what I'm looking at, for future reference.................THX. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted December 19, 2014 Share Posted December 19, 2014 correct, original caps would not be splayed, if you buy this, the first thing I would do is send the block out and have the line bore checked, whenever you do anything to the line bore, it needs to be checked!!! Quote Link to comment Share on other sites More sharing options...
Murphy Posted December 19, 2014 Author Share Posted December 19, 2014 Most definately Sam, but I'm not ready to pull the trigger yet on any motor changes, just looking & educating myself. Thanks again! Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted December 19, 2014 Share Posted December 19, 2014 It has splayed main caps. If it is .030 over it is probably done. 040 is about max on a factory block not a lot of room for clean up. Two bolt blocks are actually stronger than the factory 4 bolt blocks in the main web area. splayed caps make them better. The last 400 I did, adding the three splayed center main caps, then line bore, squaring the deck, then boring, was pretty high dollar. I probably could have picked up an aftermarket block for a little more. Quote Link to comment Share on other sites More sharing options...
Ynot Posted December 28, 2014 Share Posted December 28, 2014 I run a 406 setup like this and hasn't let me down. Except that whole LS conversion calling my name Quote Link to comment Share on other sites More sharing options...
Murphy Posted December 28, 2014 Author Share Posted December 28, 2014 So the splayed caps won't weaked an already thin web area? Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted December 28, 2014 Share Posted December 28, 2014 they will help it 1 Quote Link to comment Share on other sites More sharing options...
SPLATT71MC Posted December 28, 2014 Share Posted December 28, 2014 The bolts that are splayed go into the much thicker oil pan rail rather than the thinner webbing. Quote Link to comment Share on other sites More sharing options...
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