bmfIROC-Z

iTrader: (1)

well my dad just bought a 400 small block from a buddy of mine and we checked the numbers on the back of the block (3951511)at numerous websites and weve seen that it came out of a 1970-73 truck,caprice,monte carlo or nova so that didnt really narrow it down,so we checked the the engine assembly/suffix code (t1026ckp)in my dads old chiltons book and found two 400 small blocks that had ckp suffix code #1=1970 nova 400 4 bolt main t/h alum. head 375hp and #2=1972 nova 400 4 bolt main t/h 170hp and i looked the suffix code up on websites and their saying it came out of a 72 caprice 170 hp ,were a little confused , who should we believe ? chiltons or the websites and if the chiltons is correct how would we destinguish if it is the 70' or 72' ? it doesnt have aluminum heads anymore but it was in a 83 camaro berlinetta with full interior and brand new 15'' bfgoodrich radial t/a's ,3.42 iroc posi rearend and 700r4 and it could light the tires up at about 30 mph no problem and its pretty much stock except edelbrock performer intake and edelbrock carb stock cam and 1.94 heads,aint no way 170hp could do that,thats why its so confusing,if somebody could help us out it would be greatly appreciated ,thanks in advance,

85Firebird350

iTrader: (3)

ON the opposite side of the block on the ledge the casting numbers are on there should be a date code. If it has a 2 in it it's most likely 72 if it has a 0 its most likely a 70. Let me know and I'll try to help.

KrisW

iTrader: (5)

I thought if you had a first digit of "t" in your code that meant GMC truck...

five7kid

iTrader: (14)

Drop the "anymore".

The factory never put aluminum heads on SB 400's.

They did put aluminum heads on 375 HP big blocks, however.

My money is on the 170 horse version. In '70, it was 265 horse, but that was "gross" HP (for reference, the 4-bbl 350 was rated at 275 horse that year). By '72, they had to use "net" ratings, and that dropped the rated number. Didn't matter, they were all the same lo-po 2-bbl dogs from the factory (I can say that - I had one).

bmfIROC-Z

iTrader: (1)

i was just telling what my dads old chiltons from back in the 70s says, if anybody has one lying around they could take a look and see what im talking about, it says there was 396s ,454s and a (suffix code ckp)1970 400 that recieved aluminum heads and both the 396 and 400 were rated at 375hp i dont know i wasnt even thought of back in the 70s so i really cant say thats why i was asking but if it is a 72 how many horsies should he get out of it with stock bottom end a good cam ,2.02 heads ,4bbl intake ,headers and exhaust? thanks for the replies

bmfIROC-Z

iTrader: (1)

ill check for the numbers on the other side of the block this weekend.

sofakingdom

iTrader: (1)

As stated, a small block 400 NEVER came from the factory with aluminum heads. Don't worry any further about that part.

In the early 70s, cars were badged, confusingly, "400". A "400 4-bbl" was a big block, a 402 which is a .030" overbored 396. This engine did not have aluminum heads either: the heads were often casting # 820 (one of the better BBC street casting cores). A "400 2-bbl" was a small block, specifically the one you have. For the first couple of years, it was "rated" at 200 some-odd HP; but then when the modern system for creating those "ratings" was invented and all of a sudden the "rating" became related to the engine's actual power output as installed in a car, the "rating" magically dropped to about 170 HP, without a SINGLE change to the engine itself. Magic, I tell you.

The engine the Chilton's is telling you about, with the aluminum heads, is a big block. No connection to what you have in any way except they're both Chevrolets.

Don't concern yourself about the kind of vehicle your block came out of. Forget the stamping codes, they are USELESS, even if you can identify exactly what they mean. It's a BLOCK. It is quite dumb; it pays no attention whatsoever to the sheet metal it's wrapped in, and above all, no mysterious and mystical essence wafts up out of the sheet metal (or, as is often assumed, the fiberglass!!) and infuses the block with some special properties. I can totally assure you, the block COMPLETELY forgets how romantic the sheet metal is to its new owner, LONG BEFORE it's even out from between its old fenders. It does not care whether it was in a Nova, Impala, truck, Monte Carlo, or what; it's a BLOCK. Since you will be putting different pistons in it, different heads on it, different cam in it, a different intake, different carb, different exhaust, and even wrapping different fenders around it, that stamping contains no information whatsoever that is meaningful or useful, any longer.

Don't get all hung up on "202" heads. People can take ANY kind of junk heads that there are, and jam 2.02" intake valves in them (I'm assuming that's what you mean?), and now they're instant "performance" heads, maybe even "from a Vette". But in fact, they're still the same heads they always were. If they were junk before, they're junk now, just with slightly larger valves installed. People who think that just because a set of heads has had that done to it are now suddenly "good", are setting themselves up to get ripped off.

Instead, pay attention to what the head castings ACTUALLY ARE. A good casting with 1.94" (stock 350 or 400) intake valves in it is better than a crappy casting (such as 882, 993, or 624 - all very common vicitims of this scam) with 2.02" ones graunched in. In fact, for a 400, NO stock heads are really "good enough"; any ones you get, will be a restriction to that many inches. The only ones that come close are Vortecs (906 or 062 casting). Rather than waste money on old ones, look at either a set of Vortecs, or aftermarket.

It's as easy as falling off a log, to get 1 HP per cubic inch out of a motor, without breaking a sweat or having to worry about exotic bottom end parts or any of that. That makes 400 HP a reasonable goal for a 400. For example, a 400 with about 12cc "reverse dome" pistons, the block zero-decked, stock crank and rods (with better rod bolts in the rods - VERY IMPORTANT!!!!), Vortec heads, a Comp XE274, Performer RPM intake, Holley 750 man sec carb, and headers, should make about 425 easily.

Don't worry about any other numbers on the block, they won't tell you anything you can actually do anything with. You already have the ONLY important one: 3951511. No others matter.

Good luck, and enjoy!!

ploegi

Sofa!!! You are a philosopher!! Thank you very much for the truly inspiring read. You have put a smile on my face, and that is not easy this early in the morning....

There is a very large chunk of wisdom in that post. Very well said.

bmfIROC-Z

iTrader: (1)

wow, i guess i dont know crap.

Codename 47

iTrader: (4)

Good call sofa. I also post this a lot on here. Chevy High Performance made 430 hp and 525 ft/lbs with dished pistons, Lunati 00010 cam, air gap intake, headers, and a holley 750 dp and vortec heads. Runs on premium gas from the pump. I've got it in my car. Works great.

The main thing you should look at is the mains. The 4 bolt blocks are weak. Find a 2 bolt block, slap some vortec heads on it and you've got yourself a pretty damn good budget build.

five7kid

iTrader: (14)

You know what? You're in the right place to do something about that.

I did my first engine install in 1969. Before I could even drive. I've had greasy finger nails for 5 decades. I've been into cars, mechanics, racing, engineering, rockets. I've accumulated a lot of hard knocks and scar tissue. I've seen the sport change dramatically, been through good times and bad.

And, you know where I've learned the most?

Right here. From people like Vader and Sofa and so many more. I've said stupid things and have been corrected (both gently and otherwise).

But, the main thing is, I've learned. A lot.

And so can you. In the long run, you'll save a lot of money not making the same mistakes others have, and you'll get a lot more out of what you do spend. Just don't think that anything is meant to be personal - we're a bunch of on-line no-face gear heads, for goodness sake, how could this be personal?

Ask, listen, learn - that's "ALL".
----------
.031" over, actually. 4.094" for 396, 4.125" for 402.

Hey, we've got to be technically accurate here, right???

bmfIROC-Z

iTrader: (1)

i didnt say anything was personal i was stating a fact that i really dont know as much as i thought i did and i pulled my first engine when i was 8years old , built my first engine at about 10years old and built many since ,my dad was and still is a greasy fingered shade tree mechanic so i grew up building fast cars mainly cutlass's and camaros but we never really paid much attention to detail , we would just find a good 327,350 or 400 small block as close to 1970 as possible for good stock compression throw a set of 2.02 double humps, street-strip cam,high rise intake,headers,good oil pump, 750 double thumper carb and of course a posi and a 4 speed and see what shed do ,so now i am paying attention to detail and it just sets me back a little knowing that i have worked on gm products most of my life and how little i actually know about them. ive only been a member almost a year now and ive learned alot and i realize we are all just a bunch of faceless mechanics here and there aint no use for getting upset about somebody over the internet but if i took something personal i woulda said so,okay

ploegi

Not necessarily the case. There is always more to learn. I have been doing this for over 30 years, and I am still learning.

AlkyIROC

3951511 is a SBC 400 block.

t1026ckp

T = Tonawanda engine plant
1026 = Oct 26
CKP = 1972 400. It had an automatic transmission attached to it. It was rated at 170 HP with a 2 barrel carb and was originally in a Caprice.

sofakingdom

iTrader: (1)

Ahhh,,, the "good old daze"...

I used to do the same thing. Still have a bunch of double-humps laying around. Still running some on some cars, in fact.

Problem is, the world has changed around us. That system no longer works the way it used to. Double-humps are getting harder to come by. People take total junk crap smogger trash scrap heads and stick 2.02" valves in them and people snap them up like they're gold (and still go slow). Little bitty motors have caught up to big blocks. Fuel sucks. CNC casting came along and REVOLUTIONIZED the head industry (because now, aftermarket heads are SUPER cheeep, like, you can buy em for less than the cost of the machine work to make a pair of double-humps equivalent to them). Cams have evolved. Valve springs are actually available now in steps all the way between "stock" and "all-out solid roller racing". And on and on and on and on....

The old formulas, while they still "work", aren't competitive any more. You gotta plug into this "continuous improvement" kind of mentality, and realize that every day, SOMEBODY thinks up something better than the day before. it's been ALOT of days gone by since those you describe.

Hang out here, read and learn; you'll see what people are doing NOW, TODAY, that works in the world we live in now. Don't worry so much about what you "know", or don't; instead, concentrate on soaking up whatever everybody else "knows", that isn't monkey-spank. Every one of us here is learning CONSTANTLY. Like five7 said, I don't think ANY of us, no matter how much we "know", can fail to learn all the time. That's the beauty of Internet message boards. All you gotta do, is learn to filter out all the strokes and other BS, and listen to the people with some serious mental and experience horsepower; there's an incredible amount of great info on here.

bmfIROC-Z

iTrader: (1)

yeah i pretty much figured that

bmfIROC-Z

iTrader: (1)

i know what people are doing these days and i know that things are always changing and getting better,thats why im here! to plug into this ''continuous improvement'' kind of mentality you speak of.

dirtywhiteZ28

Alright since it seems maybe we've got that all out of our system, how about a thunker.I recently swapped out my original '84-LG4 305 with a LG4 305 that I was told it came from an '84 chevy p/u. It has a knock sensor on the pass. side. Unfortunately the weather here in houston is crappy. I'll check the rear cast numbers later, but the front number tag say's V1206FCU. I've have spent most of the day looking on the net for some light but no luck so far. There is a couple of nicks in the lower stamping so all I can retrieve is _F12_755.

Beast407

1970, 1971, 1972 400 small blocks all had 4 bolt mains from the factory and three core plugs on each side instead of the standard two. Factory 400's after 1972 came with 2 bolt mains. Also after 1972, most 400 small blocks had three freeze plug bosses per side, but some had only two bosses machined for plugs. I have not seen any rhyme or reason as to why.

When swapping heads remember that all 400 blocks are siamesed bores and require steam holes to be drilled into the head decks for any vestige of street operation.

bmfIROC-Z

iTrader: (1)

THIS MIGHT HELP YOU I FOUND IT ON A FORUM


V1206FCU
V - Flint Engine Plant
12 -DECEMBER of 1985
06 - Day
FCU - 1985 1/2 and 3/4 ton pickup truck 305 (5.0L) 150 HP and matched up to a manual trans RPO LE9 NOTE-This engine code only used this one year.

dirtywhiteZ28

Thanks for looking, your the only one so far that I've heard from that found a match for that FCU suffix. I got this motor for a 12-pack of Michalobe. Then talked the guy into letting me use his shoplot to do the swap. I saw the LG4 stamped on the back but was to busy thrashing wrenches to write things down. It's no barn burner but runs better than my old one did on just 7 cylinders. Timing chain jumped.

bmfIROC-Z

iTrader: (1)

NOT A PROBLEM MAN

five7kid

iTrader: (14)

I wasn't upset. I was hoping you weren't thinking we were a bunch of know-it-alls trying to put you down (seen it happen). Body language is pretty hard to read on the internet.

Looking up those codes takes more patience than I've got. I tend to take the "dumb block" approach and let the casting # be the end-all - until driven further (like trying to figure out why my '87 LB9 cam retention plate wouldn't fit my ZZ3 block).

While I still had the 305, I often longed to have that 400 SBC back. I had traded my brother cars, he gave it to his son, who abandoned it in Topeka, Kansas. It had about 350k miles on it by then, still stock bore. Ah, the ones that got away. . .

bmfIROC-Z

iTrader: (1)

its all good man ,i gotta new question 4 ya ,while we were cleaning off the pistons we found a .040 stamped in the top of the pistons ,i would guess this means that it was bored over .040, my question is about how many cubic inches would a 400 bored .040 be? we were wonderin just for ***** & giggles, any insight would be appreciated.thanks in advance.

ploegi

Probably somewhere in the neighborhood of 408.....

ljnowell

wow, that one is pretty much done. hope it doesnt need any macinework on the bores.

sofakingdom

iTrader: (1)

Yup; the scrap rate on 400s gets pretty dramatic at .060" over. Especially on those early blocks, and more so if it has core shift in the casting as they often do. And even more especially if it wasn't well taken care of for the first 30 years of its life (poor coolant maintenance).

Get it sonic checked before spending money on it. Not much sense in paying somebody to scrap it out for you by boring out what little metal might be left. Or, if you're lucky, hopefully the bore is runnable as-is (or close to it... just a quick hone).

bmfIROC-Z

iTrader: (1)

shes just fine ,no machine work needed besides some honing.

Supervisor42

I never could figure out how the "Kid" knew so much about old iron.
Now it makes sense. You're like me & Sofa...
how do you say it,, Well-seasoned