I have been looking at parts for my engine, and I have noticed that there is a late model sbc and an early model sbc. how do I know what is in my car? It was put in 2 owners ago and I cannot get a number for the guy who did the work... I have a 1989 Camaro RS with a 355 in it. How do I find out what year the engine is? Or at least if it's a late model or otherwise...
I can provide pictures if needed...
Thanks

 

there are numbers cast into the block on the driver's side. They are on the back of the block where the transmission mounts.



take these numbers and either post them on here or google them

 

Late blocks will also have 5.0 or 5.7 cast in that area; early don't have those numbers

 

Those are relatively hard to get at when the engine is installed... lol
3970010

 

https://www.thirdgen.org/forums/engi...g-numbers.html

Since that block was used from '69-'80, it could be any one of those years. What parts are you looking for? Very few are determined by the year of the block.

 

Jegs lists a lot of their parts in different groups... oil pans seem to be specialized, among other things. I'm not really looking for anything in particular right now, just trying to make an accurate "wish list." I'd like to get more power out of it, but need to fix the little quirks it has, if I can. It seems underpowered to me...

 

Heads, cam, exhaust. What do you have?

 

I don't know for sure what all has been done to it. Like I've mentioned before, I'm the 3rd owner and cannot contact the guy who put it together. I know it has headers and 3 inch stainless exhaust, flowmaster muffler. My mechanic said he's pretty sure it's got an aftermarket cam, and the rear end has been re-geared, but not sure what that is at either. The speedo was off about 30mph when I got it. Holley carb/intake, standard rockers. I'm assuming the heads are stock too, but I'm not sure.

 

That block is in the category usually known as "early" nowadays.

THe heads could be anything, from 1955 to 2000, since they all interchange. Same for alot of the other parts. Just because they "interchange" DOES NOT mean that they are "the same" though. There is a HUGE variety of stock as well as aftermarket heads for SBC. There are a couple of hundred factory head castings alone that will bolt to that block, and probably a roughly equal number of aftermarket ones. These run the gamut from stock 265 2-barrel ones in 1955, through the high-compression high-perf ones of the 60s, the crappy smogger garbage of the 70s, the ones that came in these cars some of which are pretty decent and some (specifically including the ones that would have come in your ar if it origianlly had a 305) are the worst of the worst, and on up to the "Vortec" ones of the late 90s. Just because you know what block casting you have, doesn't tell you much about what engine you have, since all heads bolt to all blocks.

Virtually ALL "rebuilt" motors have aftermarket cams in them. Nobody in his right mind would buy a "stock" one from the dealer. Even if a "stock replacement" is desired as it often is, stock replicas are available widely, at a fraction of what GM would have to charge.

As far as gears, what it the first thing a sensible person does after buying a "new" used car? Stop reading, and think for a minute.

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It's catch up on overdue maintenance, right? And what sort of things are included in that? Would you say perhaps, change the lube fluids? Of course you would. So while you're changing the rear end fluid as you now know you will be doing in the very near future, look at the gears while you have the cover off and see what they are. No other method of determing gearing is as accurate, and no other method also accomplishes the more important goal of renewing the fluid.

 

Here is what i discovered when i was trying to find out info on my used small block.Like in the post above there should be a gm5.7## on the top off the block on the driver side near the trans.I also found numbers near those about a inch away inward.gooled engine info or something like that and found out what the other numbers were. Mine were J127. Made in Oct--J, 12th, 1997--7.I knew 97 because the guy i got it from told me it was late 90s.I dont know how hard it is to see the numbers you have in the car.Hope that helps. Bryan.

 

He already has the casting #. Post #4.

 

Pull the valve covers and get the casting #'s off of the heads. The head casting #'s are posted in the sticky as well.

 

Any recommendations for a replacement Diff oil? I'd like something high-performance without breaking the bank. I'm planning on going to a full-synthetic oil, unless anyone has a reason not to.

 

Mobil 1 75W-90, about $15 for enough to fill your axle

If it turns out to be a posi with organic friction lining, add a unit of the GM (no other will do as well) additive, before putting the main fluid in.

 

It's not posi, mechanic called it a "one-wheeled wonder." I'd like to put a Detroit locker in there, after I figure out the gear ratio. And when I have the money. I got ambitious and took a valve cover off today, here are the casting numbers. Towards the back, it has 3998993 and under that it says 124 with a little dial (/) followed by a 72. In the center, it says GM 5 and CONV4. Towards the front end (driver's side) there was another little dial with the needle pointed towards the "0". PLEASE tell me these aren't the P***y 1970's headers... And if they are, I'd like a recommedation on what to get to replace them with. I've seen several different kinds, but have no idea what all the numbers mean when you're shopping for them.
Thanks for all the help I've gotten on here, this forum is pretty amazing!

 

Is the only number that matters
Google "3998993 heads" and see what guys say

Typical comments
https://www.thirdgen.org/forums/post...655-post4.html
http://www.hotrodders.com/forum/what...s-125251.html?

 

Sounds like these heads are pretty worthless... What do I replace them with? From what I've been reading, the smaller the combustion chamber is, the more compression/power you have... And aluminum is better than cast iron? Does anyone have any suggestions on what to get?

 

993 is pretty much trash. There's actually 2 versions of it; one is some of the original mid-70s deep smogger garbage, the later is the "hecho en mexico" version that comes on the "260 HP" Goodwrench motor that's a direct copy, part # for part #, of the deep smogger 350 motors that made 160 HP installed in vehicles all through the 70s.

As far as what to get, that's kind of open-ended... what house should you get? Gee I don't know. Start at the beginning. What's your budget? What's your goals for this car? What pistons are in that block? Is the short block in good enough shape to be spending money on stuff all around it, or do you need to rebuild that as well?

 

I'd like to build an "everyday driver" that I can also take to the track on the weekends and do OK. I'd like to get a set of heads for less than 1k, considering I still need a good set of roller rockers. In one of the posts I read on a different forum, they replaced these heads with a set of aluminum L98 heads off of a Corvette for $400. I have yet to find a deal like that. When I bought this car, I was told the engine was a 355, but the casting number is for a 350. Is there still a chance that it has the better of the two? As for pistons, I'm not sure there either. My mechanic said he was pretty sure it was bored 30 over, so I'm assuming it has new pistons in it as well. It was installed less than 2 years ago, but I don't have the time and space to tear it all apart and see what she's got. We're currently renting an apartment, and my garage is full of tools, storage and motorcycles. So basically, I'm learning as I go, and hopefully I won't have to rebuild the whole engine from the ground up. So I'll take any advice on what anyone else has for heads, pros and cons of what's out there to buy, or any general pointers that may just plain come in handy.
Here's what I've been looking at:
Brodix: http://www.jegs.com/i/Brodix/158/1021001/10002/-1
World: http://www.jegs.com/i/World+Products...250-2/10002/-1
World: http://www.jegs.com/i/World+Products...660-1/10002/-1
What's the difference between a straight plug and an angled one? Which has more power? Are the heads I'm looking at good, or am I WAY off base?

 

There's not really any such thing as a "355". A "355" is just a 350 that's had its first maintenance overbore of .030". I'm not sure why people call it that; seems a waste to me. IMO it's only appropriate to deviate from the factory CID designation if the whole combo is non-factory, such as a 383. But just something that's had a little freshening up doesn't really "need" a new size number. It's still a 350; it just has 355 CID now. It's not "better".

The Brodix heads are a decent product. I'd use something besides World; theirs while an OK product are really old-school, have got passed up by alot of the other mfrs. Dart and TFS are others that would be worth a look, in that price range. Or, you could go with Vortecs; a pair of them from Scoggin-Dickey, already set up for a good cam, are around $600. They require a Vortec-specific intake though.

The 113 aluminum heads aren't too bad, but not great either. I wouldn't pay more than $400 for them.

Another option you might consider is Edelbrock. Their heads are EXCELLENT street heads, even though they will NEVER win a "most power" contest. That's not what they're designed for. Avoid their cams and carbs, but their intakes are possibly the best there are, and their heads can be a good choice for a STREET motor.

But before you buy heads, or a cam, you ABSOLUTELY MUST find out what pistons are in the motor, and it'd be a smart thing to also measure the deck clearance on all 8 so you can know ACCURATELY what your compression is likely to be.

Angled plugs point the spark plug over toward the exhust valve, which is a better place in the cyl for igniting the mixture. The difference in modern heads is very slight however; it was a BIG deal in the over-the-counter factory performance heads of days gone by like the 292, but with more modern designed chambers, it's less of a big deal. Still, people want it, because of the lore and romance, so the mfrs make them that way. One thing about that is, some headers will fit MUCH better or worse with one or the other, so that's one thing to watch.

 

What is "deck clearance?"

 

The distance between the top of the piston face and the top of the deck surface on the block, when the piston is at top dead center. From GM, as stock, its usually about .020 to .025 deck clearance. Lots of people will have the decks shaved slightly on the block when its being rebuilt, mainly to make sure they are absolutely flat, but also to reduce the deck clearance to maybe .005 or so for their new pistons. This is called 'zero decking' even though its not actually .000 clearace.

 

Short of totally disassembling my block, is there any way to tell what pistons are in it?

 

Just pop the heads off. No need to take apart the block.

Stock, the deck clearance (how far "down in the hole" the pistons are at TDC) is usually about .025", usually more. You'll find, especially in the 70s blocks with the incredibly crappy quality control and machining tolerances that we had to put up with back then, that it can easily very as much as .010" from one bank to the other and/or from front to rear on the block, usually in the "greater" direction.

VIRTUALLY ALL "rebuilder" pistons ADD .020" to the stock deck clearance. They do this because many blocks require HEAVY deck cutting to clean up damage such as from scouring due to a blown head gasket that the owner kept driving anyway. In such cases, if the clearance were returned to stock, the piston might actually hit the head. Most rebuilders couldn't care less if the compression is a little lower, but they'll be mad as hell if they get a comeback from the other thing. Guess which piston design is preferred. Yup... and I'd guess that odds are 99% or better that your short block has the extra .020".

There's no way to know from outside. Just pop the heads off. Not a big deal at all. Then you can observe & measure quite easily and accurately.