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3 Posts
Discussion Starter · #1 ·
hey all,

i have a 79 Fleetwood Brougham daily driver that i would like to beef up and restore but due to having to smog this year i am a bit hesitant as to what is legal etc. Nothing fancy just freshen up the engine a bit, improve flow and exhaust etc.

could i install a dual catback exhaust without violating smog? etc etc

any cali cadillac experts im in need of some pointers :)

its a real nice car no rust, perfect shape no accidents, strong engine etc but if i cant do anything performance related or have to worry about touching anything due to smog i may elect for a 74 or previous which are exempt here.

thanks for any info/help on this

94 Fleetwood Brougham
7,528 Posts
Oooh, California upgrades... These are more interesting.

How much inspection do they do? Visual and tailpipe? Or IM240?

Well, couple of things, some to do for full time, and some that you will likely switch back at emissions testing time. You have to be creative in CA....

Full time mods:
1. I would look at things like recurve ignition. Get advance in faster. That most always helps.
2. Look for aftermarket CARB approved intake manifold if they exist.
3. Freeflowing catalytic converter. Remember, it is a violation of Federal Law (likely CA too) to remove a FUNCTIONING catalytic converter. Replacement cats must be in the same location and you can't add more or less than OEM equipped. BUT, if you do put on a new free flowing cat, it can upset Backpressure EGR operation, depending on which type it has depends on how bad. Postive backpressure EGR's often don't agree with low restriction exhaust.
3. Cat back exhaust, ~should~ be a non issue. Fed emissions doesn't care what you do after the cat. I don't think CA does either. But you will have to custom do one. If you have lost of $$, and Impala SS system should work with lots of mods, but it is an expensive job.
4. Fed Emissions doesn't allow you to touch from the CAT forward LEGALLY. But often it isn't checked, so no one cares. In CA, they check.
5. Head porting, full time, and likely a good benefit.
6. My HEI EMR mod will help speed up timing, (check the Tech Tips section). Then you can narrow up the gap between initial and mechanical timing.
7. Adjustable or at least the fed emissions vacuum advance can. CA is a more restricted can to keep advance at cruise lower. Just bringing up initial advance will help, but if you can't, the Fed emissions vacuum advance can will help part throttle drivability.

Part Time Mods:
1. CA emissions requires EGR to be functional at WOT, Fed emissions doesn't. WOT is pretty much open game in 49 state cars (well, 48 now, as NY has adopted CA emissions last I heard). So there is something in the EGR line that will keep vacuum to the EGR valve when vacuum drops to near zero. Look for this, either remove it or defeat it.
2. CA likes a lot of EGR, so you might consider attempting to eliminate it. But you will fail emissions test if you try to pass w/o it.
3. Advance camshaft, or replace with better grind. Keep overlap down, 54 degrees or less. Overlap allows raw fuel to go out tailpipe causing high HC emissions. Get a grind that matches a newer engine that makes more power. So, like a LS7 Vette cam is designed for 7L engine, might be an interesting one to look at, but likely duration is way too high for the slow revving 425.

Just a start....

3 Posts
Discussion Starter · #3 ·
they are supposed to do a full visual inspection but ive been to shops where the guy looks like he has inhaled too much exhaust and can barely hook the test machine up :)

also one of my mechanic buddies has a personal guy he goes to that will of course not bother with the visual but if he retires or whatnot i dont want to be left with a great car that is "illegal" and wont pass smog. what a joke this emissions crap is.

i have not had to do much with emissions before my other car is a 1973 plymouth roadrunner 340 (pics at if anyone is interested)

my previous cadillac was a 1972 coupe de ville but it was pretty dinged up, had rust and would have required more money than i had to fix it up :(

i suppose the easiest thing to do is find a solid pre 1975 smog exempt cadillac but the fleetwood is such a smooth driver...

maybe ill just freshen up the 425, do some of your tips posted and redo paint/vinyl top and keep cruisin.

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