Cast Iron or Steel?

[77K10Silverado]

Little help here.. I plan to pull my original 350 4bbl from my 1977 K10 for a rebuild but was curious what type of crankshaft came factory. Cast iron or steel? So far I was able to get 010 off the side of the block which tells me its a 4 bolt main. If I need to get more numbers I can. Any help would be appreciated!

[MountainGoat1966]

To begin with, I have seen many 2 bolt blocks with 010.
My stroker engine is one of them.
If memory serves me correct, cast cranks were the most common ones installed by the factory.
A lot of people swear the steel cranks are stronger, and in some ways they are, but they are also more brittle and the flexibility of a cast crank can be very forgiving and provide a longer engine life.

[bdiamond]

I agree with the 010 being on both two and 4 bolt blocks. What I have noticed is that most of the 4 bolt blocks I've seen have a small pipe plug for the oil passage above the timing cover about 1-1:30. Most cranks are cast. You might be able to see a die parting line at the rear face. A thin sharp one is cast a wide flat one is steel

[Just call me Sean]

I thought the same thing about that little plug by the timing cover, but I was told that also is not an indicator of four bolt mains.

[MountainGoat1966]

All the small blocks I have owned had the 1/8" pipe plug at the top of the timing cover, on the passenger side. Two and four bolt mains.
The only way I know of to determine 100% if a block is a 4 bolt is to remove the oil pan.

[KQQL IT]

Unless you're going to make 450+ HP cast crank will be fine.

[esbstuff]

Originally Posted by KQQL IT

Unless you're going to make 450+ HP cast crank will be fine.

Ditto... However all 70's 350 trucks were suppose to be 4-bolts.

Also 010 could me its a 302 (Chevy). The block casting number was recycled my GM. You need to check the block code and casting date to be 100% sure.

Now before everyone gets real excited and starts tearing their trucks apart... The block code is on the pad behind the alternator and since GM only built a few 302's (a few 100... maybe), its more than likely its a 350...

[MountainGoat1966]

I'm not gonna run outside and tear my truck apart, I work on it enough already.
My stroker is built from a '72 block, I thought it came from a truck but I could be wrong. I suppose the next time I do tear the truck apart I will look at the casting numbers and stamps.
It's a 2 bolt.
With a cast crank.
It has well over 70,000 HARD USE miles on it and has held up very well.
Everybody told me I needed a 4 bolt.
........ Right...

[KQQL IT]

My 2 bolt 400 has made 25 passes in one day.
12.0xx drive it there drive it anywhere.
Buy good parts and don't look back. And the biggest radiator you can get.
Order mine for a '79 1ton 454

[77K10Silverado]

Thanks for all the responses friends. It doesn't matter if it 2, 4, or 157 bolt.. I'm gonna use what's in the truck because it's matching numbers. My friend who is going to do the rebuild was just asking if I could find out by coding my engine. I think I'll have to drop the pan to really answer both of those questions.

[50seven]

0010 blocks are a dime a dozen both 2 and 4 bolt main. It could be a 350, 327 or a 302 but I doubt it is anything more than a 350. the suffix code stamped in front of the pass side head behind the alternator will give you a better idea (the partial VIN is stamped there beside the suffix code also). look at the harmonic balancer if it is the big diameter thick style it is a 350. The 327 & 302's typically had very thin smaller diameter harmonic balancer.

All cranks are steel they are either forged or cast but the are all steel.

Have heard some builders say forged cranks and 4 bolt mains are overated unless you are making big horsepower. apparently 4 bolt mains can weaken the block so instead of spinning a bearing on a 2 bolt main your block grenades with a 4 bolt main. I'm not into the big horsepower so it really doesn't matter in my case.

[77K10Silverado]

Here's the side of my block just if anyone wanted to see...

[50seven]

That is not your casting number for your block. It is probably a date code or a mold number. Your casting number is at the back of the block behind the driver side head. You will probably get more info from the suffix code I mentioned earlier.

[motornut]

it's back here,and mines a four bolt

[RoughKuntry]

The 350 4 Bolt Main that I have states Late 1972 Early 1973 350 v8 Block :P guess I got lucky.

[BigBlocksRule]

I haven't seen a "matching numbers" Chevy truck. I have an '81 Corvette that is a matching numbers deal, last digits of the VIN are stamped on the block deck on the passenger side, just in front of the head. They're also stamped on the tranny.
I haven't seen any pickups with the VIN stamped on the deck which is what it takes to have a "matching numbers" vehicle.
If your engine builder decks the block (which most good ones will do), the numbers will disappear.
Don't get wound up in using the same engine that's in the truck, it won't make a nickel's difference.

Side loads on the main caps increase dramatically with a stroker. I've seen a lot built with 2-bolt blocks, also seen several of those in the shop for freshen ups with cap walk and bearing damage. If you can find one, use a 4-bolt. If the 3 center caps have "2482" cast into them, they're nodular caps and indicate a better block, these are sought out by performance guys.

KQQL IT, you realize there's a world of difference between a 400 and 350 block, right? Most builders won't use a 4-bolt, rumor has it they're weaker due to location of holes in the main webs.

[esbstuff]

Car companies used to let blocks set or season before doing the final machine work. This also let casting flaws come to light before the block was used. As in the case of late 87 early 88 350 truck blocks that had a crack in the #1 cylinder. The crack was in the water jacket and let a small amount of antifreeze into the oil or get burned.

A casting date of 3 to 6 months (maybe a year or better depending on production variances) before the production date of the vehicle is usually considered a "Matching Numbers" motor if the manufacture did not stamp vin numbers in the blocks.

Years ago I had a 1970 Torino GT Convertible. The casting date of the engine was 10/68 and the bearings were dated 11/68. Everyone that was familar with Fords of that vintage said the engine was 'Matchinig Numbers' to the car at that time. I was later able to verify though prior owners that the car never had an engine transplant.

I will have to disagree with BigBlocksRule on one point. A 'Matching Numbers" vehicle will also comand (depending on market and time) a greater price than a "Non-Matching Numbers" vehicle UNLESS the engine swap was done at a dealership and you have paperwork to prove the replacement was done. A Corvette I recently looked at was considered "Matching Numbers" even though the engine had been replaced. The owner had paperwork to prove the car had a new engine installed under warrenty way back when so it was considered a 'Matching Numbers" car. Also, my father owns a couple Model A's, so I keep an ear to that hobby as well. Very rough Model A's with "Matching Numbers" (frame and engine) bring crazy prices these days... always more than decent to nice drivers. Granted right now our trucks are to a point a new or rebuilt motor truck is considered a plus. But if I were planning to keep or keep and restore a truck, I would sure keep the orginal motor and transmission if it all possible.

[BigBlocksRule]

How could you prove that an engine had or hadn't been replaced? With no VIN stamped on the deck, there's no numbers to match. Just because it was cast in the few months prior to the complete build, there's no proof that it is even original to the vehicle. Parts may be all correct for the period, but the only true numbers that can match are on vehicles whose VIN is stamped on the deck. Anything else is just numbers-correct, which is most cars and trucks. The Corvette guys tend to be more crazy about this than just about any other group, theirs are judged right down to the right wax marks on parts. An engine swap is not generally counted against scoring as long as they have the documentation proving it was a warranty swap.
At any rate, if it's a 2-bolt block, most would recommend swapping for a 4-bolt main block, it can take more punishment than a 2-bolter.

[bdiamond]

Don't all blocks regardless of what they go in have a partial VIN stamped on the pad by the head? I was under the impression that date codes were just used to assume matching numbers on things like heads and manifolds.

[RoughKuntry]

I have the original papers that came from Ft. Lewis Wa. Stating the Truck left the base with original motor from Plant in California. My 73 Spent most of its life as a Police truck. Due to the fact of the front axle being a Dana 44-50F. I have 99% of the paperwork except for the Rebuilt carb that I did 2 yrs ago. Since that time, I have done updated full wire harness's from the Engine Bay to the tail lights, The truck doesn't look like a 73, however, Vins are allowed to be swapped due to weather here in Wa, Not an option to re-fabricate the whole bottom of the cab. The fact of all of this, is I prefer to rebuild my 350 4 bolt main, then spending money on another motor that cant take a beating.

[BigBlocksRule]

All blocks have a code stamped on the deck, but all it identifies is what kind of vehicle it went into - truck, passenger car, etc., plant it was assembled at and a few other particulars. Only part of 'em actually got the VIN - all Corvettes, first and second generation Camaros, Chevelles, etc. I've never been able to find a partial VIN on a truck block, but I haven't spent a lot of time looking since the "numbers matching" thing only seems to be meaningful to folks with collectible cars.

And to throw another monkey wrench into the mix, in 1955, the VIN that was used to register pickup trucks was on the engine ONLY - there was no VIN tag on the vehicle. Once the original engine was swapped out, the "VIN" as we know it was gone.

[RoughKuntry]

Its still funny how most people look for all matching vins, I can tell ya that my truck doesn't have the original transmission because its swapped out with my M22 4 Speed Manual. But I love the truck anyways. There is a way to get around the emissions test at the DMV, By pulling your original vin number from the cab you can place it in the exact same place on a different Square body and proceed to call it an Original. I was told this by The Licencing Place. It's Ironic.

[BigBlocksRule]

^ can't swap the VIN in Texas, they'll get you for truck rustlin'...

[motornut]

Originally Posted by BigBlocksRule

^ can't swap the VIN in Texas, they'll get you for truck rustlin'...

Same here, didn't think it was legal at all.
i couldn't keep my "texas" burb ,somebody did that to......
to keep it the police would have to re-vin it.
thank god a drunk hit it!