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tatoodkelt

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Discussion starter · #1 ·
Just picked this up over the weekend. I was wondering if there was any way of finding out what type of vehicle it came out of. The site I found to run the casting number just said "72-80 400". Any know of a good site to decode it?

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Discussion starter · #4 ·
Had to pick up the mother in law at the airport after work last night. Didnt get out into the garage to get the number. As soon as I get home today I'm heading out there. Thanks guys.
 
Discussion starter · #6 ·
racecar100 said:
Most 400's came out of any big cars like caprice impalas and both 2x4 and 4x4 turcks.
Click to expand...
Yeah, the last one I had I pulled out of a 71 Impala.
 
#7 ·
we did a 406 for a buddy that runs up at capitol raceway, so far he has ran 10.615 @ 127mph with stock crank,stock rods, flat top pistons and 283 heads with good stainless steel valves and a solid flat tappet cam
 
#10 ·
racecar100 said:
Most 400's came out of any big cars like caprice impalas and both 2x4 and 4x4 turcks.
Click to expand...
They also came in Malibus and Monte Carlos from '73 until '75 or '76. Caprice and Impala stopped using them after '76 and trucks had them '73 thru '80.
 
Discussion starter · #11 ·
OK. Here's the numbers I pulled off the motor.

Casting number - 330817
These numbers were all in the area for the engine ID

C6F218571 T0712TLS
1112971


Thanks guys!
 
#14 ·
Here's all those codes:
TLS 75 400 Truck 175 LF-4 TH-400 4-Brl 4X4
TLS 76 400 Truck 175 LF-4 TH-400 4-Brl 4X4
TLS 77 400 Truck 175 LF-4 TH-400 4-Brl 4X4
TLS 79 400 Truck 170 LF-4 TH-400 4-Brl California

I'd suspect the 76 from the 6 in the VIN but check the casting date.
 
#16 ·
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#17 ·
1966_L78 said:
I have heard this before, but I wonder:

Is the 4-bolt just weaker than a 350 4-bolt, or is the 4-bolt 400 actually weaker than the 2-bolt 400? And how much weaker are we talking?

I thought it was something to do with the outer bolts going into a thinner part of the block webbing... But wouldn't the inner 2 bolt still be as strong as a stanfdard 2-bolt block?

I could see where the outer bolt holes could make the webs a little weaker (less material), but how often does the web actually break (or flex enough to cause problems) because of this minor reduction in material?



I currently have a 400 SB in a project car... Standard deck with suffix and VIN... Casting (mortec) indicates possible/probable 4-bolt block (-511 casting?)
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=
I feel the 4 bolt 400 is the least desirable one for performance engines
Yes I have seen a number with cracks in the webbing right at the outer hole.
Any 2 bolt the passes sonic testing is just fine & any 2 or 4 bolt one is fine for milder stuff
But the outer bolts make the webbing weaker & they are prone to cracking if you lean on them
Again, for most any mid RPM milder under 450-500 HP deal any of the blocks are fine
I do not like anything over .040 preferably less
I do prefer a 2 bolt block over a 4 bolt in a 400
If you are going to get serious splayed caps is a good idea
Stock block with studs will handle quite a bit more then the General intended though.
Yes the deck is prone to cracking from the steam hole to the head bolt hole

My preference in order
A 2 bolt with splayed caps
A 2 bolt with studs
A 2 bolt with bolts
A 4 bolt with studs
A 4 bolt with bolts

I have not really found much if any difference between different castings as far as strength or wall thickness.
 
#18 ·
I agree with wolfplace. Even if we build a bracket 355 engine we start with a 350 2 bolt block then buy splayed caps, you end up with a much better piece. And second, people think they have a gold mine when they have a 4 bolt main so your gonna pay more for a 4 bolt block, chances are your gonna pay less for a 2 bolt main and have a better unit to start with.
 
#20 ·
Wolfplace said:
=
I feel the 4 bolt 400 is the least desirable one for performance engines
Yes I have seen a number with cracks in the webbing right at the outer hole.
Any 2 bolt the passes sonic testing is just fine & any 2 or 4 bolt one is fine for milder stuff
But the outer bolts make the webbing weaker & they are prone to cracking if you lean on them
Again, for most any mid RPM milder under 450-500 HP deal any of the blocks are fine
I do not like anything over .040 preferably less
I do prefer a 2 bolt block over a 4 bolt in a 400
If you are going to get serious splayed caps is a good idea
Stock block with studs will handle quite a bit more then the General intended though.
Yes the deck is prone to cracking from the steam hole to the head bolt hole

My preference in order
A 2 bolt with splayed caps
A 2 bolt with studs
A 2 bolt with bolts
A 4 bolt with studs
A 4 bolt with bolts

I have not really found much if any difference between different castings as far as strength or wall thickness.
Click to expand...
Hmmmmmmmmm, Either Mike and I share the same brain cells, or, we just think alike! :D
Over the years, after building several SB400 engines, all of which were built from stock Chevy blocks, I am in complete agreement.

Also, and until someone shows me a casting date to make me change my mind, ALLLLLLLLLLLLLLLLLLLLLLL 70-72 model SB400 blocks were 4-bolt ONLY. Then, for the 73 model, ALLLLLLLLLLLLLLLLL SB400 blocks became 2-bolt only, all the way up to 1980.
There were NO 70-72 2-bolt blocks, and there were no 73-80 4-bolt blocks.
 
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