Geeze...I am using a 207 casting 2 bolt block with a cast crank in my 355 road race engine that is turbocharged. No issues yet and 500ft-lbs torque at the rear wheels, and close to 400rwhp. Motor is sold tonight hopefully.
Go with a crate motor. Got a warranty and $for$ it's going to be cheaper than having a SBC rebuilt Panhead
They may be different, but my guess the numbers on the front of the block are not related to alloy content, since they show up as the last 3 of the casting number on all different kinds of blocks....if you see one that says 509 on the front what does that mean? seems to me that it means that the mold for the front of the block was used on a 400 block, since that casting number ends in 509. I would not buy an 010 block assuming it's a four bolt without having the pan off and counting bolts. they made them both ways. Most were 4 bolt, some were 2 bolt. although it doesn't matter for 95% or more of the engines we deal with.
The very best bet is to look for a 96-98 chevy truck or van motor with the 880 casting. They are some of the strongest blocks ever made, have PM rods, roller cams, vortec heads and a factory windage tray.put a performer manifold, 650 holley and a set of headers and you'll have about 350 hp.
i agree that it doesnt guarantee a 4 bolt main, it also doesnt guarantee that it is a high nickle or a high tin block. In fact in my expierences heathen is pretty close to the mark lets take a look at a couple of blocks in the shop this tunnel rammed engine has a casting number of 3956618, mortec and your basic casting number books will tell you this is a 350 2 or 4 bolt main. it is in fact a 4 bolt......also along with the production casting numbers under the timing chain cover it has the casting identifier of .010....this number also appears in the rear of the block. this casting identifier shows us that this block had 1 percent more nickle added to the mix when poured. the number or numbers as we will see later on will appear under the timing chain cover and on the rear of the block. and the number .010 appeared nowhere in the exterior casting number now we have a 3970010 block but no where on the front or back does it have .010 .....this a good 4 bolt block,very desirable, but it is not a high nickle block. the block on the left also has the casting number 3970010, but looking at the front of the block we see .010 and also .020 mixed in there with the other production casting numbers......when we roll the block over we see the numbers are repeated on the rear. this set of numbers tells us that this block had 1 percent more tin and 2 percent more nickle added....this is probably the most sought after early production block out there. you will see that there is also a production casting of 509, even tho this is a 350 block and there are no 509 in the casting number now , while we have the 2 bolt sitting next to the 4 bolt, i grabbed a dial indicator and measured the main webbings of both blocks...i found them to be nearly identical......although the 4 bolt has more material machined off in the register area for the wider cap, and drilling that second hole is gonna remove some material from the webbing..{this is why splayed caps that go into the block area at an angle are stronger} the 4 bolt webbing is in no way thinner than the 2 bolt so it doesnt matter what casting number you have, they could be 2 or 4 bolt , and you are going to have to pull the timing chain cover, or check the rear of the block to see if it is a high nickle and or tin casting the nickle was used to improve the strength of the cylinders and the tin was added to help the metal flow into the casting, resulting in less porosity in the block...i have noticed a difference in the machining of the higher nickle blocks as well as the wear on tear downs, they tend to retain the hone pattern longer and show less wear if the block has .010 only it has 1 percent nickle if it has .020 only it has 2 percent nickle if it has .010/,020 both, then it has 1 percent tin and 2 percent nickle these numbers will be in the timing chain cover area AND the rear of the block i also agree that 90 percent of the time a 2 bolt main and a cast crank are more than enough for the builds we see on the street Fred
I feel like i'm in good company! while you guys are myth busting could you check the reckwell hardness of a Vortec block{880} vs a 010/020? I've seen more than one vortec with hone marks after 80,000 miles and I don't recall that from the blocks of the past.
i think i have some factory specs on the "rockwell" hardness of the vortec, if not, i know a guy that did some testing on them for endurance teams early in their life, i know they did test very good. i will call him and if he has the data, and if he does I will forward it to ya.
Thanks for the info....although I disagree with what you're saying. When you try to solve a mystery, it seems to me that you should not ignore any of the evidence. In this mystery, there is a rumor that certain casting numbers in certain places denote the alloy content of the casting. I contend that this rumor is false, based on evidence that you seem to be ignoring. Lets look again at this block: I contend that the pattern that was used to make the mold for the front of this block, was also used on the following blocks (from mortec): 3959512....327...62-67...2...Was also used for some "CE" replacement blocks 3959532....283...64......2...Used for some "CE" replacement blocks 3970010....327.....69....2...Trucks and industrial 3951509....400...70-71...4 3970020....307...69-73...2 Do you think it's kind of an odd coincidence that there are five numbers on the front of that block, only two of which you contend relate to the alloy content, yet all five of them are used as the last 3 digits in actual block casting numbers? (note: I had never noticed the existence of the 512 and 532 blocks, I saw the numbers on your pic, and went to mortec fully expecting to find the numbers and sure enough, there they were! amazing coincidence, eh?) Question, again: What does the 509 mean up there? I thought you said it was a 3970010 block? I'm sure the guys at the foundry have better things to do than to take the time and effort to put numbers on patterns that don't mean anything. If so, then the other numbers that you want to ignore actually do mean something....what do they mean? Now, we'll get back to the 3970014 block I showed a pic of earlier, it's hard to see but it has the 010 and 014 numbers in the timing cover area. If you are correct, then this 2 bolt low perf 350 block contains 010 of something, and 014 of something. And I also ask you to see if you can find a 307 block. I expect you'll find the 010 and 020 (and probably 509) numbers on it too. Did they really go to all that trouble to make a 307 (which only ever came with a 2bbl on it) with the special alloy? If you can find someone who actually worked at the foundry back then to explain that I'm full of crap, and maybe cough up a Chevy blueprint explaining that the last 3 digits of the casting numbers of certain (but not all) blocks is related to the alloy content, then I'll believe you. But it's really stretching, imho. Even my old 1970s Chevy Power manual, which is supposed to have all the factory secrets, doesn't mention this.
i have some factory performance books that the factory sent out to their backed trans am teams.....let me dig them out and i will scan the text and forward it to you.....it make take we a little while...it lalso shows what all the casting identifiers represent on the front and rear of the blocks. Fred
Special alloy? It's nickel and tin....you're probably carrying some around in the spare change in your pocket right now. Not that special and I'd say that it's really not that expensive to add to the casting mix. Thanks for taking the time to post the pics and your text, Fred. I've got a '69 2-bolt block in my shoebox (355) with all ARP hardware. I abuse the living shit out of it every time I get behind the wheel, and it's held up great for a year now. Also....those of you who posted that he should just buy a crate motor (Deuce Roadster, Panheadguy) should realize that most REAL HOT RODS don't have crate motors. They have engines that have just as much blood, sweat, and tears put into them as the rest of the car. Crate motors are fine for the average street rod, however.
I realize that, but according to the myth it seems to be special enough that they went to a lot of trouble to put it in certain 3970010 blocks, but not others.... What it boils down to is that I think that Fred's engine building ability has far more to do with how long they last, than what the funny cast numbers are on the blocks he uses.
I tend to agree...because I personally don't think the block casting matters all that much either, but I'm also not a professional engine builder. I like the fact that a professional such as Fred takes the time to answer questions like this one. I have no idea if the numbers mean anything or not, but if I had a choice between a block with the 010 / 020 casting and one without, then I'd still pick the one that had it just for the hell of it.
I can't understand why guys in the USA even bother building a motor up from bits, when there are so many good, warrantied, proven crate motors available for chump change from reliable major suppliers. Unless you want an unusual motor, of course, or just like building 'em. I just wish we could get good crate motors in the UK for a decent price
I can't speak for anyone else, but I enjoy rebuilding engines. Not much compares with the first time I ripped an engine to pieces, replaced what needed replacing, reassembled it, installed it, and it actually started and ran! Face it, there are complete cars out there that I could buy, license, and drive, but for me, the building is a good share of the enjoyment. Remember, any idiot with a decent credit rating can buy a new Corvette--but it doesn't make him anything but a new Corvette owner. I can more understand people like yourself going the crate motor route; you probably don't have as much raw material readily available to you as I do.
Hey man we are on the same page, I am realy pumped about this motor cuz Iwant to do the assem myself and see how its gona run,its gona be cool. Maybe it will be junk I dont know but Im gona give it a shot. KDUSTERS CC.
nothing cooler than hearing that motor come to life when you know you took it apart and you assembled it. Regardless of how much $$$ i would save over building from scratch i'll stick to building my own motors....that way i know that it is done right and if something goes wrong i can only blame myself.
yeah, I don't understand how someone could buy a crate motor when they could build one. Buying it already done takes all the fun out of it. although I did buy one crate motor in my lifetime....and immediately tore it apart and redid it. Buying an LS-7 assembled used to be a gonga deal, much less expensive than buying the parts that went into it.
I'd probably pick it too, because it would be an early block, from back when the 307 was still in production. The later 010 blocks don't have the 020 on them. At least if my hypothesis is correct
hahaha....i think we will agree to disagree, not to beat a dead horse to bad, i want to clarify some of my statements. according to my myth, only the .010 and the .020 correspond to the tin/nickle.. and the will be present on BOTH the front and rear of the block...yes there will be other numbers there and some times the last 3 digits of the casting number will be there...such as the .014 you see, but it doesnt mean there is .014 more of anything there. i have 2 .014 casting blocks in the shop right now, niether of them have the .010 in the timing chain area/rear of block also , I am only talking about the 350 block...the 307 is a completely different animal when it comes to casting identifiers, also the main webbing is different in those blocks, I was commenting on the 350 block as i thought that is what the thread was about...so everything i said pertains to the 4 inch bore 350 block. Fred
so...if you saw a 307 block that has the 010 and 020 in the timing cover area, the nickel thing doesn't apply? (of course not, it won't have the 010 in the rear area, since it's not an 010 block) As I hinted in my last post, I think you'll find that the numbers are there because that's what blocks were cast with that front mold pattern, and it's likely that if they did make better 010 blocks, they would have been made during the performace era, late 60s-early 70s. So they'd have the 020 there simply because they were made when the 3970020 blocks were rolling down the conveyors along with the 3970010 blocks. I'm eagerly awaiting the factory info, when you do get it scanned.
I hope you will post the factory casting number info for all of us to see. I am looking for a suitable block to rebuild right now so this info would be appreciated. Thanks dave
Hell yeah, I've built full motors before, and it's a buzz when they fire up first time and run great, but just sourcing the core motor, then finding all the parts is such a ball ache over here in the small country. If I could pull a base motor from a breakers for a hundred bucks, then order parts that would arrive in a few days, then I'd be building all sorts of wild motors.
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