I've got two small block Chevy blocks I'm need to find the year and original engine size for. Casting numbers are:3858174 and 3970010. A guy might be interesed in trading me a block for a four speed for my coupe but wants more info on what they are. I figured somebody on here would have the casting numbers right at thier fingertips and be able to help me on this deal.
3858174 is a 64-67 327cid small journal out of camero, truck,or passanger car. 3970010 is a 69-72 block some are 350's and some are 302's out of the same type of cars and trucks as the other. I hope that helps.
Mortec.com.... 3970010....302.....69....4...Z-28 Camaro 3970010....327.....69....2...Trucks and industrial 3970010....350...69-80...2 or 4 Very common block!!!
brad...not to hijack this but ive got an 010 block in my car its a 4bolt main truck block. does the number differentiate 2 bolt vs 4 bolt mains?
But - only when you can find one. It seems the older they get, like everything else, availability begins to dwindle. Gary 4T950 Chevy Guy
the pad on the front.....thats where the make or break money maker numbers and letters are at......brandon
chevy put millions of 010 blocks in trucks, and a handful into Z28 camaros...the odds of finding a DZ block are lower than getting hit by lightning. most 010s are 4 bolt, a few are 2 bolt. They were mostly used in 1970s pickups and suburbans.
most 010s are 4 bolt, a few are 2 bolt. They were mostly used in 1970s pickups and suburbans.[/quote] From what I remember reading the 010 casting was an indication the block had a 4" bore. It could be a 2 or 4 bolt main. Most of them seem to be 4 bolt. I think the real key to knowing the value is the stamping on the front of the block.
Most 010 blocks are actually 2 bolts. It was the standard 4" bore 350 block used in everything until 1980, when they started using 207 castings as their main 350 casting - a lightweight casting. So all those 350 2brls, and standard performance 4brls in cars and light trucks are 2 bolt mains. It was only definately a four bolt in Hipo or heavy duty truck applications. Most 1/2 trucks with an automatic had 2 bolt mains. Most camaros had 2 bolt mains. All vettes had 4 bolt mains. Other than that, there is no no definiates. Only way to tell is to pull the pan and look. Best blocks were usually 3/4 ton or bigger stick shift trucks,or early 70's real high horse cars. They will usually have a 010 in the timing cover meaning that 1% extra nickle was added for strength. If you are real lucky you find a 010, and a 020 under the timing cover. That means 2% extra nickle was added for strength, and 1% extra tin so it would pour nice with the extra nickle. Most of these also came with a forged 1053 steel crank. Old marine motors are also excellant because they got all the factory heavy duty stuff in them.
Yea, tell me, I bought a '64 chevy pickup for $800 bucks and it had a DZ 302 block and the matching 186 double humps. I was pretty stoked, bought the truck for the heads and my buddy needed the front clip and bed, but I was surprised about the block. Guess it was just my day.......
huh, things must be different up in Canada? I've taken apart a lot of 70s chevy pickups at my jobs at a junkyard, garage, and machine shop, and only noticed one 010 block that had two bolt mains, but I've seen a whole bunch of 4 bolt mains. And almost every 70s 1/2 ton truck 4bbl 350 I've worked on was 4 bolt main. I have seen a lot of 014 two bolt main 350 2bbl engines....
there should be two number sequences stamped on the block, just in front of the right side head, on the deck surface. The info there will tell you what the engine is, what year/ model vehicle it's from, etc. if you have the books to look it up. Go to the www.mortec.com web page, and print out the casting numbers for blocks....the 305, 307, and 400 used different block castings than the 350, you can look look them up when you're shopping. if it's a 302 block and has "DZ" stamped on the front (as in F0325DZ) then either it's a 350 block that's been decked and restamped to get big bucks, or it might be a 302 block. That stamp is the only difference, although the date code cast into the back of the block should also match.
another way to tell if it is a four bolt of 2 bolt main is if there is a removable alen head plug above the oil filter. this is a good indication it is a four bolt main if that is there. i have been told that GM put it there for a secondary oiling system to keep the engine cooler.
maybe your thinking about big blocks, which generally have larger holes on 4 bolt main engines? this doesn't apply to small blocks
Casting number gets you in the neighborhood, number on the front pad puts you on the money. I'm at one of the few Chevy dealers that still has the old parts catalogs and can track down blocks by the letter codes if I get some spare time. PM or email info and I'll try and help out. Robbie
You can tell 99% of 400's because they have 3 freeze plugs in the side instead of two, or they will have a hump where the 3rd plug would be located...........The last, if your lucky is a 509 casting block it won't have the 3rd freeze plug or hump but it will say 509 on the side of the block where the hump or plug would be. I hope this will help you out, this is how I have found all of mine without having casting numbers handy........Also as far as castings they will end in 509, 511, or 817. Just let me know if I can help you with something..........
305 usually has "305" or "5.0" cast into the block on the trans mounting web behind the distributor...well...not directly behind, but in that area.
The 3 digit numbers on the ends of the block appear to me to indicate that the mold for that part of the block was used on blocks with those casting numbers. That is, the same mold was used to make the ends of the 3970010, 3970020, and 3951509 blocks.
I seem to only find 2 out of 10 small blocks are actually 4 bolts.Only way to tell is drop the pan.....
The Jalopy Journal
