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87 K5 TBI engine choices...

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87blackblazer

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I'm in the beginning stages (mostly planning, considering, pontificating, dreaming, researching, and learning) of (hopefully) a body-off restoration of my wife's Blazer. It has the stock 350 TBI w/ 200k+ miles. Since we live in Comifornia, I have to keep it smog legal. I'd say my skill level is somewhere around novice with engine mechanics and for that reason, I like the idea of a crate engine and would like see at least 300 HP / 375 TQ. I know that there are many, many choices for the SBC, but not so many when you have to keep it smog legal (can you pass smog w/ a 383).

What are the options / suggestions for the rebuild?
 
Well, in California, externally it has to appear stock, or you will fail on a visual. And obviously you have to keep the smog pump and cat.

Now what you do to the inside of it is your business. A 383 can pass smog, it's mostly in the cam. But for what you want, the Vortec headed crate 350 from Chevy will fill the bill and pass smog with flying colors, You'll only need to pick up the apropriate TBI Vortec intake from Scoggin Dickey, swap your acessories (or get new ones), and get a chip for it.
 
What about the cam makes the engine less smog friendly?

When you say must "look" stock visually, how close to original are we talking? It seems like any type of SBC would appear original as long as there wasn't a six-pack sitting on top :eek1:
 
87blackblazer said:
What about the cam makes the engine less smog friendly?

When you say must "look" stock visually, how close to original are we talking? It seems like any type of SBC would appear original as long as there wasn't a six-pack sitting on top :eek1:
Click to expand...


Cam's with alot of overlap, or even long duration, will let more of the exhaust out unburned. Fortunately those are the types of cams that are less offroad friendly.

As for visually, you're right. Your average referee doesn't know if it should have aluminum head's, or if he's looking at a 427 or 267 small block. Pretty much, swappiing for a mild crate motor will fly right under their radar.
 
Any chance either of these might pass the muster: http://www.blueprintengines.com/popular_configurations/index.html?topic=options&pcsci=5

All of my current emissions components are functioning correctly and I would swap them over (and possibly replace some of the sensors). I know they're working b/c it currently passes smog and I just spent mega bucks on the EGR this summer.

I saw the footnote regarding the 454 injector and high pressure fuel pump. What effect would this have (if any) on the smog test? Obviously it would be visually different.
 
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The smog inspector has a book with a picture of your motor. He checks for every hose,wire, heat shield, etc.

I installed a vortec 5.3/4L60E in my 1987 Blazer a few years ago and took it to the referrie station. It passed and I got my sticker but they checked- everything.

My neighbor put an electronic ignition system on his 1977 international truck and he ended up registering it in Arizona because he never could satisfy the CA smog inspectors.
 
You did a motor swap, that's going to catch attention. A small block sitting where a small block belong's is fine. To a referee a small block looks like a small block.
 
I know that it currently passes yet I can say for a fact that not every heat shield and wire are in their original configuration. The emissions components are still intact (in fact, I spent mega bucks fixing the EGR a few months back when the grounding strap rusted through under the dash).

Here's an interesting engine: http://www.online-racer.com/chevy_383_stroker.htm If you read the article, it only got 11 more HP. I know that it would have dramatically improved low end TQ, but 11 HP doesn't seem worth it. Interestingly the emissions numbers are WAY below max allowable, making me think that you could be more aggressive with component selection.
 
Having lived in SoCal most of my life and dealing with the smog laws, a couple of suggestions.
  • Avoid anything that looks aftermarket such as chrome parts.
  • Paint your aluminum heads and intake.
  • Make sure your parts are all C.A.R.B. legal and have the appropriate documentation with you so can fly by.
  • Go to a smog station that is recommended by enthusiasts so that they can guide you through making it pass legally. And make sure they do the visual before hooking it up to any machines, so that if there is a problem you can fix it before you get flagged in the DMV.
I have an '89 Jimmy with a stock motor and an S-Trim Vortech Supercharger. It passes emissions but visually they don't like it. I was flagged by the DMV on the visual and have had to smog it every year as opposed to every two years like normal so have the C.A.R.B documentation/ paperwork at hand.
 
I read the article. The 11 hp increase they are talking about. Is over a stock 96 vortec head engine. Not a 350 TBI engine.
That 383 puts easily puts 40- 50 or more Hp to the ground than a stock 350 TBI engine. Plus a huge increase in torque. Well worth the money IMO.
That article is also a little misleading because they state that the 383 has vortec heads.
The block shown in pic and at the machine shop page has TBI heads(#193). Altho GM called early TBI heads vortec heads they are not the same as the 96 and up L31 vortec heads. L31 heads flow better than TBI heads at higher RPM
Putting L31 Vortec or some World Torquer heads on that 383 would up the HP/torque even more. But would require some tuneing to get the chip right to meet smog. Also you will give up some fuel MPG.
IMO....TBI is better to modify than later model CSFI because you can use bigger injectors and larger CFM throttle bodys to make more power.
With the L31 in the 96 burb in the article you are limited to 19lb hr injectors. As far as I know there are no aftermarket larger injectors made for CSFI. That 383 would make a lot more power with 24lb injectors and a good tune. So the info in the article really does not apply to a TBI truck which are easier to modify for more power.

That is a good price for that 383 engine. I think if you installed it in your Blazer you will like it.
It would also be fairly easy to get a chip burned for that engine as shown. With the proper chip It should pass CAL emissions no problem. Visualy there is absoulity no difference between that 383 and the engine you have now. I would put it in exactly as it came without any performance mods like cam heads ect. The TBI heads are great heads for a truck they are very clean burning, make lots of low end torque, and get good gas milage doing it. The cam is computer frendly and may even run OK on the stock chip until you can get a new chip burned for it. Or have it dyno tuned which is the best way to go.
 
I'll have to dig up the actual link to the rule, but for engine swaps on all vehicles later than 66 (I think) the motor has to be from the same year and type of vehicle (You can't put a v8 in a car that only have a 4-cyl option.)

But they don't check compliance on anything older than 1975 which is why pre-smog vehicles are so desirable.

Edit: Here's the text from Novak:

http://www.novak-adapt.com/knowledge/tj_swap.htm

“Engine changes are legal as long as the following requirements are met to ensure that the change does not increase pollution from the vehicle:
• The engine must be the same year or newer than the vehicle.
• The engine must be from the same type of vehicle (passenger car, light-duty truck, heavy- duty truck, etc.) based on gross vehicle weight.
• If the vehicle is a California certified vehicle then the engine must also be a California certified engine.
• All emissions control equipment must remain on the installed engine.
After an engine change, vehicles must first be inspected by a state referee station. The vehicle will be inspected to ensure that all the equipment required is in place, and the vehicle will be emissions tested subject to the specifications of the installed engine.
“Engine changes are legal as long as the following requirements are met to ensure that the change does not increase pollution from the vehicle:
• The engine must be the same year or newer than the vehicle.
• The engine must be from the same type of vehicle (passenger car, light-duty truck, heavy- duty truck, etc.) based on gross vehicle weight.
• If the vehicle is a California certified vehicle then the engine must also be a California certified engine.
• All emissions control equipment must remain on the installed engine.
After an engine change, vehicles must first be inspected by a state referee station. The vehicle will be inspected to ensure that all the equipment required is in place, and the vehicle will be emissions tested subject to the specifications of the installed engine.
Click to expand...
 
When it comes to swapping small block's, my motto is, what they don't know won't hurt them.

The earlier advice about avoiding chrome, braided line's etc. is good advice. DOn't do anything to tip them off that anything other than the stock 350 is in there and they won't think twice about throwing it on the roller's.
 
In CA, they have a diagram of all the emission hoses in the engine compartment and they check each one so you need to make sure the new hoses and sensors matches the old stuff too.
 
So, a 383 would be okay, but try to keep it "stock looking." I take it black paint and OEM valve covers are in order. What about the intake - just paint it hi-temp black? Could you get away with a Holley TBI replacement or would that raise suspicions and possibly even emissions?

The visual check seems a little redundant. If the ultimate goal is to reduce emissions or at least not allow you to replace an engine with a more polluting one, then the rollers should be ultimate (and only) evaluation needed. Use the standards for the OEM engine and be done with it... That being said, I've never actually watched the smog check. I've only dropped it off and come back to pick it up with either a large bill or a small one.
 
I'd suggest taking a car in to have it smogged or go with someone who needs it and watch what they do.

They don't just look at it for a few seconds and see if anything looks out of place and move on. They look at a diagram and check each and every hose on the diagram and make sure it's hooked up on your motor in the exact same way. This means if you put in a radically different motor which uses stock equipment hook-ups different than your old ones, you will fail because they don't match. Also, if anything is out of place or missing or not hooked up, you fail. You don't even get on the rollers/sniffer unless you pass the visual. The visual is actually harder to pass than the sniffer unless your motor runs really poorly.

Unless your really good, you won't be able to fool them without some cash bribes. Even then it's not likely.

This doesn't mean you can't do an engine swap, you just need to go to a referee and have them check everything to make sure the new motor complies with all the laws before getting it smogged If you have a CA donor motor, it'll likely be ok as long as your truck had a similar size motor option when it was new.
 
There is no way anyone could tell if you put a 383 in your truck if you replace it with a block from a similar year. There is no diference between a 1 piece seal later model 350 and a 383 except internally. Where nobody can see without tearing apart your engine.
If you get an after market manifold get an edelbrock. They have a CARB# and paint it black. Cant tell them from stock. Except for the "Edelbrock" cast into it.
IMO I would not use a holley TB. Better to get a bored out stock TB. If you do get a holley TB you will have to get an adapter for the 2" bores or get your manifold machined out to 2". Plus with a stock TB you can get parts anywhere. With the Holley if something breaks . Its mail order and wait
A bored out stock TB will give you 600CFM that wil work nice with the 383 you are looking at.
BTW stock TB is only 480 CFM.
 
Interestingly, that is precisely the intake manifold that is on that crate 383. The only thing bad about that setup is the Silver Seal chrome steel timing cover, oil pan, and valve cover. I'm sure they'd be happy to put on OEM products ;)
 
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