400 SBC Casting

[Mark Uptergrove]

Hello! The folks at hotrodders told me to head over here for some info. I have a 400 SBC that has a 6 digit casting ID. It has clearly 395509 on the block, but obviously most are stamped 3951509. Thanks!

 

[Philip]

There is a space where the 1 should have been. My guess it was left off the marker tray used when casting the block. Whether intentional or not we will never know, it still is a 509 block with a unique difference.

 

[Mark Uptergrove]

Thanks! So this is will be a 2 bolt main if I am not mistaken?

 

[Philip]

Yes it will be a 2 bolt main. If desired the caps could be changed to aftermarket 4 bolt caps that use a splayed outer bolt configuration and having the block aligned bored.
It is said that the 2 bolt main block is stronger than the factory 4 bolt. I built a factory 4 bolt main 400 using ARP main studs. Power output was in excess of 425 hp and 500 lb ft and was spun to 6000 rpm with no issues in the 6 years I had the car. If not exceeding those numbers the 2 bolt caps will work just fine. My 406 was tame enough for the streets and had plenty of power to enjoy at the track, and as a side benefit would get nearly 20 mpg while cruising at 75 mph with the AC on.

 

[Mark Uptergrove]

Allow me to ask another question although a little more involved lol. I asked about this block, due to it being available. I currently have a 1985 SWB that came with a 305. I swapped it out for a 400 SBC 3591509 block 2 bolt main. I then converted it to TBI using the ECM out of an 89 truck with a 5.7 and had the knock sensor disabled in the ECM. It has a high rise manifold, full headers, whole 9 yards! It runs good except it has developed a pretty nasty piston slap when cold. I could run it until it blew up but heck that wouldn't be fun. The block I originally asked about is one that has been bored over .40, roller rockers, and pop up pistons, and double hump heads. Could I take my engine out, put the intake, TBI, valve covers, headers, etc on it and be good? Thanks again!!

Picture of what I have in there before I converted to TBI (1406 performer)

Pictures of engine #2

 

[Philip]

Not sure why you would disable the knock sensor on a computer controlled engine. By doing that inaudible detonation could be destroying the engine and may be the reason for the noise on cold start. The 5.7L TBI is probably a little lean for the 400. The build of the blue 400 may not be optimum. Domed pistons with small chambered heads is going to be a lot of compression, probably over 11:1. which is more than you can run on pump gas. With those heads using a dished piston would be optimum. That would put your compression around 10:1 with better street manners. BTW those are circle track valve covers and do not vent the crankcase well.
The 406 I Ibuilt with the numbers posted above were in a 512 block that has been zero decked, had 12cc dished pistons on stock 400 rods with a factory nodular iron crank. A Lunati 60103 cam, AFR 195ST heads with 65cc chambers. A quadrajet carb on a performer manifold with a GMPP HEI distributor.
If you do not already own that 400 in the photo above I would pass. Better to start with a standard bore 400 block and build to street friendly specs. The 400 you have may be rebuildable. To know for sure it will need be torn down, inspected and then could be rebuilt to the power level you want. Doing that would insure that you were getting the best motor for the money invested. And if you are going to use the TBi set up also use the computer controlled distributor and all the sensors to get the maximum performance from the set up. The throttle body unit and injectors from a SS454 truck will boost performance over the 350 TBI on it now.
What type of tuning software do you have?

 

[Mark Uptergrove]

Thanks. It sounds like even at $350 I shouldn't purchase that engine. I thought I could use my valve covers and everything but the compression definitely sends it over the top. The piston slap when it is cold was happening when it was carbureted, I think it just got a top end overhaul before I got it. Compression test were decent, but one cylinder on the passenger side was lower. I have a Burn 2 Chip, and due to the noise of the camshaft on 400 (no roller) It was recommended by a few to disable it. I also disabled VSS and EGR. It really runs great and smooth, but I will keep my eye out for a 454 TBI. I use TunerPro RT. I managed to get a profile that doesn't kick off the CEL and run smooth. I am sure there are a ton of room for tweaks! Do you think vortec heads with drilled steam holes would make the compression on my current engine too high or do you see a benefit from it?

 

[Philip]

If you have stock heads and bottom end the compression is low. Dished pistons with 76cc heads, around 8:1. The Vortec heads have a smaller combustion chamber and would increase the compression, but some have small valves and small runners. Not familiar with them so cannot recommend a decent set. Steam holes are good idea regardless of the head choice.

 

[Snappyglide]

I'm having a problem trying to figure out what year my 400 is the casting number is 3951509 , it is a 509 block, the partial vin on engine is CBJ190867, and engine code is FO802TTD Any help would be great

 

[Philip]

The date code is on the back of the block on the bellhousing ledge, it is the casting date. It will be a letter followed by some numbers. The letter is the month, A= January, B=February, etc., the next number is the day of the month and the last is the year.
The 0802 in the FO802TTD is the date it was assembled in the year of the casting date.

 

[Jlars21]

Hi all,

I have a 1977 Chevy Cheyenne k10 with a 400 small block. Bought the truck last year and am rebuilding it from ground up. Trying to get more information on the engine and where it came from. It's not the original. The engine block casting numbers are different from what I'm seeing everywhere on websites. On a stamped plate it has 6H25 and then above that it has a triangle of letters from bottom left to top to bottom right: DAN.

Any ideas? Thanks in advance.

John

 

[Philip]

John more info will be needed. The numbers stamped on the block in front of the passenger side head and the casting numbers and the date codec on the bellhousing ledge.

 

[Jlars21]

Ok I found this drivers side of the casting...GM #3970010

 

[Philip]

That would be a 350 block.

 

[Jlars21]

That's what im finding everywhere based on the #...but it has a harmonic balance on the front and the guy who i bought it from told me its a 400...

 

[Jlars21]

So it's turns out it is a 350. I found all the other codes below. Any help decoding the rest would be appreciated.

Rear drivers side of engine: 3970010 (350 small block)

Front passenger side of block has two codes: C71101718 (?) & K0827TYU (Ontario, august 27, 1975 van/bus 165hp 4 bolt)

Side Passenger side below head: 6 H 25DAN (?)

 

[Gary]

I'm trying to find out what year my engine is horse power an all the stamp num is. V11i5we

 

[Gary]

Can't figure this out

 

[Philip]

Without knowing the year it is either a 283 (1965) or a 307 (1968). Either 175 hp or 200 hp and originally in a pickup truck.

 

[Gary]

It is in a 1979 elcamino the i got it off says it a 350 vette motor im not sure