do heads matter when it comes to emissions?

i currently have a 83 z28 that originally came with a 305 i got the car without a motor so im putting in a rebuilt 350 it has a mild cam and dished pistons...i want it to pass as a 305 emission for the smog test so thats y i didnt do much on the rebuilt...

the engine came off a 1980 truck...
the engine passed smog in my 83 camaro just passed smog before the rebuilt...
the heads i have on it are stock 350 heads (462624)...

i was just wondering if i would still pass if i put LT1 heads on it?..the heads will come off a 94 camaro that through a rode...

i wana put the heads on it 2 get more power...

but would the heads fit?...

 

those LT1 heads are not a bolt on but they can work with
modifications-cooling system is different on the LT1 and
there are other differences as well.
The LT1 heads are a more modern design and might
actually inprove the emission test results besides having
higer compression and better flow than the old '2624
heads.

 

Heads matter. Mostly for emissions reasons, it's a matter of compression. The higher it is the more power it makes, but the tougher it is to pass emissions.

Given that your truck motor with dished pistons and big-chamber -624 heads is probably down in the low 8s for compression, you can certainly swap on a set of smaller chamber 64cc heads and still pass with little difficulty while making more power at the same time.

When getting emissions tested you want to keep the spark advance very modest. Stock specs, even a little less. After you pass, crank up the advance some more for better drivability, fuel economy and power.

Agreed with above, late mdel LT1 heads won't work. They ONLY work on LT motors that have reverse flow cooling. For an older Gen1 engine you need Gen1 heads (standard flow cooling). Aftermarket Gen1 heads are all over the place- there are many to choose from both factory and aftermarket.

 

ok thanks guys...thats all i wanted to kno...

now my question is does anyone one which are better flowing heads for my Gen1 motor?...

im interested in sum descent heads that will give a bit more power and a bit of better flow...

anybody know which ones r ok or good that i can use and that will also help me with emissions?...

 

anyone???..

 

What's your budget. Good SBC heads are everywhere- both factory (Vortecs, for instance) and aftermarket (Dart, AFR, etc.). Speed costs. How fast you want to go?

 

i don't want 2 go super fast since i want it as a daily drive...i was thinkin sum stock 14014416 heads or have them ported...so i can still pass smog since i live in cali...:/...u kno...

 

Use some l-98 heads instead of the 416's if you're going to run a factory set.

 

ok...i want the 416's bcuz i kno it came out on the "HO" engines...and from wat i have read the 416's heads r ok...how r the l-9 heads?..r th7ey better then the 416's?...i just want sum good stock heads that came out 82-84 cuz i wana still pass smog...

 

The l-98 heads flow around 199 cfm at .600 lift with good flow numbers throughout the lift range which is important for power. They were on newer vehicles, so they'll pass emissions testing. If the 416 heads were better than the l-98 heads, they would've put them on the corvette instead.

 

Don't take a chance. Ported 416s are your best bet.

 

o ok thanks i didn't kno that...ok so now u changed my mind....ill go with l-98 heads....do u kno where i can find sum?...do u kno the casting number on the l-98?...

does anyone have a set of l-98 heads?...

 

ok i will like 2 find sum 416 heads...and just put them on rite now...but I'm having no luck finding sum...:/..

 

Lets not use that logic you know they put the 882 heads on a vette motor too didn't they?

In stock form the 416 heads are not something I would put on a 350 I expected to pull hard up top. They have potential, but not until you've had a grinder in them and put bigger valves in. Once done you will have invested a lot of time and probably $300-$400 into them (mine were $320 but you may need more/less work). That is in aftermarket head cost territory.

But compared to what you have now it would probably peak slightly higher but make more under peak with the 416 heads. They have like 250-275hp potential in stock form.

 

ok that 250-275HP isn't bad...I'm not planning on makin a race car i would like 2 get sum power out of my daily driver u kno...

all i wana is wat heads will i b able 2 get sum more power out of and still pass my smog test...

if i get my cam specs will that help?...

 

They did at that doom86. I'd take the 882's over the 416's too though

Try the classifieds search function to find l-98 heads or even the 882's. Stock heads should pass emissions too. The 416's could be made to make power I suppose if you wanted to do some work on them, but the l-98 or 882's will make power with only a fresh valve job. Since you just want more power for your daily driver, then less head work will equal more play time

 

ok ok ic...thanks...so ether the l-98 or 882 heads will do correct?...


do u kno the casting number on this heads?..

 

But, but, but we're talking California here. 3rd gen l98 heads are centerbolt valve cover. If the tech guy knows his chevys that might send up a red flag that there was an engine swap. Then if he becomes suspicious he might look closer and notice the driver side dipstick. If he's already put your vin in the computer he would have to "Fail", now the State knows you did an illegal swap and you're on your way to the referee. But first you have to get a legal engine in there. Corvette l98s use the aluminum pre 87 perimeter bolt heads but they have no egr provision chancing a NOX failure when testing. I just wouldn't chance it with l98 heads. Odds are you would get away with it, but it could really be a problem if you didn't.

 

yes yes......i dont want to take that chance...im trying to make this 350 look as much as i can 2 a 305...all i want is so good early heads to throw on it...maybe port them if i have to...

so l98 heads r out of the question...

looks to me its gona b 416 heads if i find sum...
help...

 

882'a were used on 305's as well. Failing you for using newer hardware than what came on the car seems to be a ridiculous outcome. When you build a kit car, you're supposed to use a newer motor to pass emmissions. So why would they fail you for using newer heads? L-98 and 882 heads are centerbolt, yes, but the 882's were used on tpi 305's as well iirc. I think the other poster is just a little on the paranoid side. Call your local government to confirm, but I'll bet they'll be more than happy to see you using newer, more environmentally friendly equipment.

 

882s are 76cc heads. I've never heard of them being used on 305s and they are not centerbolt valve covers. Yeah, the smog police might like the fact that newer heads are used but the L98 heads are for a 350 TPI. 83C_CamAroZ28 is trying to conceal the fact that he swapped in an older 350. When you do something like that it is best to attract as little scrutiny as possible. If I were a smog tech I would have no choice but to FAIL him. I would spot it about 30 seconds after I opened the hood and I wouldn't risk my license by letting him slide. If I were 83C_CamAroZ28 I would be paranoid of running into someone like me.

 

it would b an fail rite away bcuz its not approved by the state ref...

and im agreeing with wat ...i do thank u for tryin to help but i dont want 2 take that risk and gettin an automatic fail and having to deal with the state ref...:/...

 

"Environmentally friendly" only comes in packages, not individual components. A Corvette L98 head has no exhaust crossover passages, so the thirdgen EGR setup won't work. That makes the emissions worse, despite being "newer".

 

so the l98 heads arre out of the question...

do u agree im best off getting the 416 heads?...and maybe getting them ported?...

 

Sorry apeiron, but the environmentally friendly comment was supposed to be a bit of sarcasm. Ya gotta excuse my sense of humor at times.

 

My bad. I thought he was using a newer 305.

 

If ANYONE tells you 882's or 624's are good heads*, nod politely, turn around, and walk away.

L98 heads are 083 castings. They have 64cc chambers and 1.94/1.50" valves. They have the exhaust cross-over passages, center-bolt valve covers, and the '87-up intake bolt pattern. They would be a dead give-away of an engine swap to an alert smog inspector. They were only used on TPI engines.

86-1/2 & later Vette L98 heads are aluminum, have 58cc chambers, 1.94/1.50" valves, center-bolt valve covers. They do not have exhaust cross-over passages. They were only used on TPI engines (and the ZZ4 crate engine). Vettes with these heads used a tube from the exhaust manifold for the EGR system. They would be a dead give-away of an engine swap to an alert smog inspector.

416 heads were used on LU5's, LG4's, L69's, and '85-'86 LB9's (all 305's). They had 58cc chambers, 1.84/1.50" valves, exhaust cross-over passages, perimeter bolt valve covers, and '86-earlier intake bolt pattern. The '87-'92 081 casting version was only used on LB9's, were identical to 416's except for the intake and valve cover bolt patterns ('87-up).

416's, 081's, and 083's had the same ports. THE SAME PORTS! If you take a pair of 416's, have the intake valve seats cut for 1.94" valves, clean up the ports per standard do-it-yourself porting guides, cut the tops of the valve guides for positive-type valve stem seals, install a good set of valve springs, (and install 1.94" intake valves, of course), put them on a dished-piston 350 with an emissions-friendly cam, you'll make more power than you would with any of the other heads listed above (even with the same work performed), and should pass smog with flying colors as long as everything else was working properly.

*If you need an anchor for your bass boat, or something to keep the spring-loaded walk-through door to the garage open to let the breeze through, then 882's or 624's are up to that task.

 

I love me a good boat anchor.

I'd stick with working the 416s if i were you, just to be 100% safe.

 

ok and thanks for the info......and i will b getting sum 416 heads as soon as i find sum......i will b getting them ported and b putting better springs...i will also b putting all the emission parts that is need...

im with ...

 

Are you paying someone to port them?

It may be economical to pay for a bowl blend but not much more then that. Just being realistic $50 an hour adds up quickly, it's very time consuming.

 

o ok...yea im gona have sum one do it for me...wat do u recommend doing to the heads when it comes to porting them?...i dont want much done to them...