400 Block casting numbers
Thread Starter
Pro
Joined: Apr 2003
Posts: 552
Likes: 13
From: Oz
400 Block casting numbers
I have just bought a 2 bolt, standard bore 400 to build up.
The casting number is 3951511.
The info at the Mortec site says:
3951511....400...70-73...4...Some replacement blocks had 2-bolt main caps
So it says its a 4 bolt, but some 'replacement blocks' were 2 bolt. Mine is a 2 bolt, so my question is, what is a 'replacement block'???
Thanks!
The casting number is 3951511.
The info at the Mortec site says:
3951511....400...70-73...4...Some replacement blocks had 2-bolt main caps
So it says its a 4 bolt, but some 'replacement blocks' were 2 bolt. Mine is a 2 bolt, so my question is, what is a 'replacement block'???
Thanks!
Melting Slicks
Joined: Sep 2001
Posts: 3,494
Likes: 36
From: Livermore Ca
St. Jude Donor '05-'06
I hardly vist the C3 section...
From what I have read, the 511 casting started out at a 4 bolt main. The replacement blocks were the 2 bolt mains. I forget the reason.
I'm getting ready to drop in my 511 4-bolt main into my 89
From what I have read, the 511 casting started out at a 4 bolt main. The replacement blocks were the 2 bolt mains. I forget the reason.
I'm getting ready to drop in my 511 4-bolt main into my 89
Burning Brakes
Joined: Feb 2005
Posts: 894
Likes: 91
400 SBC Casting-No Problems
Years ago I used a 400 SB in my son's '66 Chevelle. He wanted to pass it off as a 350 so we specifically used the later 2 B.M. and it was internally balanced so it appeared as a 350 SB externally. I put an ARP main stud kit with a windage tray, cast 400 crank, 5.700 rods, 10.5:1 forged pistons, and a 230 x .480 cam. Car ran on pump gas (at the time) and cut 12.2's all day long at 3620#. One drawback, it was built on a budget, so I used #993 canadian heads and ported them big-time. I tried to get a friend of mine at the time (Bill Mitchell) to give me a couple of the original "Cast-iron Dart" prototypes, but they weren't ready yet. In any event the car ran excellent and was constantly in the winners circle. I shipped the head gaskets to Fel-Pro engineering for analysis, as my son used nitrous quite a few times. The gaskets
"hung out" for 4 years with no problems also. Car ran 11.1/11.2 on
the bottle with a Turbo-350 and 4.10-12 bolt rear.
Thanks, Gary in N.Y.
PS With todays technology the car would probably be deep in the
"nines" somewhere. The heads we used were really what I considered to "junk", but it was all I had with a large enough chamber, at the time.
"hung out" for 4 years with no problems also. Car ran 11.1/11.2 on
the bottle with a Turbo-350 and 4.10-12 bolt rear.
Thanks, Gary in N.Y.
PS With todays technology the car would probably be deep in the
"nines" somewhere. The heads we used were really what I considered to "junk", but it was all I had with a large enough chamber, at the time.
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
Actually the 4bolt 400 Small block has a reputation for cracking main webs and the 2 bolt 400s are prefered to 4 bolt models. The 2 bolt can be converted to a 4 bolt model using splayed outer bolts that are stronger and less prone to cracking the main webs (this has been proven by sprint car users for years.) The 400 4bolt small block should never have a problem in a "street strip" application but for racing, I would go with an aftermarket engine block.
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Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
Originally Posted by Coupe89
From what I have read, the 511 casting started out at a 4 bolt main. The replacement blocks were the 2 bolt mains. I forget the reason.
Duntov was looking for 400 C.I. due to GM policy of 400 max. C.I. for the mid size & small cars. See How the Corvette got the Big Block on my website.
