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Hey guys. I have been looking to increase my horsepower in my 305, but the problem is I live in California. So I have to be careful on what I do to it, so I can still pass smog. Anyone that lives in CA have any ideas or has done this? I don't want to start buying stuff to find out I'll fail smog.

Thanks for any help.
 

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Well
I’m pretty sure ur screwed to be honest

on a side note. I bet a 290 hp crate engine from gum would run just fine and pass emission sniffers.

there won’t be any way they can tell visually it’s not a 305
 

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Well
I’m pretty sure ur screwed to be honest

on a side note. I bet a 290 hp crate engine from gum would run just fine and pass emission sniffers.

there won’t be any way they can tell visually it’s not a 305
This is what I was originally thinking. Getting a brand new 350 and dropping it in, and the smog guys wouldn't be able to tell. But I kind of want to keep the original motor in it for some reason I can't explain. It's treated me good, so I guess I don't just want to toss it.
 

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what rearend gear do you have ??
what transmission ??
Agree! Changing the rear gears to 3.42 will make it feel like you've added 100 hp, is pretty cheap and easy, and is completely legal. One of the best mods you can do. Couple that with an OD auto trans ( 200-4r is a direct bolt in), and you'll have lots of performance without too much of a change in mileage.
 

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Swap gears to at least a 3.08 or 3.23, steeper if you have or switch to OD. Not much else you can do to a 305 other than enjoy the smooth way it slowly delivers economy. (I’m kinda used to mine-not the slowest car I’ve lived with, nor the quickest).
Patrick
 

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Torquer s/r heads
Mild cam
Edelbrock headers. The ones that thy stopped making. I found several sets when I bought mine.

about all you can hope for
 

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E-Rod would be the ticket, but i've heard of more than 1 person slipping a 350 in place of the 305. Or you could just move..... lol
 

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Before we fled, er left California for Texas (build circa 2009, left in 2012), I built my 87 SS LG4 305 up CA smog legal.
You most likely won't run into actual emissions issue from what's coming out the tailpipe as the visual inspection is what causes most of the problems. You need to have all emission control pieces that came with the car still in place and functioning—ccc quadrajet and distributor, smog pump, egr valve, the myriad of check valves, and of course of catalytic converter and single exhaust. You could drop a 350 in and most inspectors won't know the difference but you'll still need all that other stuff to pass visual. If you wanted to drop anything newer in like an LS swap, you'd need all the emission controls contemporary to that motor or the vehicle said engine came from. I've heard more than a few nightmare stories about swaps and dealing CARB arbitration. E-rod's great if you have 12–15k to drop on a new motor, trans and emissions set up, I'd def consider it.

That said, i mostly followed this blueprint:

I did mine all at once but in stages i'd do it in this order:
Rear end: 3.42 or 3.73 as other have mentioned this will instantly "wake up" the car. You won't make more power but it'll feel quicker and more driveable.

Exhaust/headers: single 3" with high flow catalytic converter, for headers you'll need a set that has air tubes. Edelbrock used to make a TES version for Monte Carlos/El Caminos but those have long since been discontinued. You could in theory have air tubes welded onto your headers of choice for visual but I didn't tell you that. There are a few in production smog compliant mid/full length headers listed as fitting 5th gens but i don't know they're specific G-body specific. Also added a Borla XS muffler.

Heads/cam/intake: Not many performance heads for a 305. I've heard conflicting info on whether LG4 and L69 heads are actually different. I put a set of aluminum Trick Flow 175 heads on with the recommended 270 cam and roller rockers. Debatable whether the Edelbrock EGR intake is worth if you have a later LG4 that came with an aluminum intake.

Monte Carlo SS/L69 ECM: if you keep the original quadrajet and ccc distributor, find an ECM out of the higher output 86–88 L69. This will giving you a little more timing and spark.

Those are the mods that will make the most difference.

I also did a couple of other things that rounded the car out nicely:
GN internals and shift kit for 200R4… super crisp shifts
dual snorkel intake from 84-86 Camaro (could be all in my head but car does seem to breathe better)

It wasn't the cheapest way to make the most power as at end of the day, it's still a 305. But I love the way my 87 drives—it's nicer and more balanced than my 71 383 or 71 Chevelle w a big block. It also keeps the engine and trans original and there's something to be said about a challenge and not doing the things the most obvious way. Of course, California kinda forces you to…

Good luck. Feel free to PM me if you want more info.
 
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