Hello all! I have a 77 Firebird with the original Olds 350 in it. Rather than replace it right off the bat I figured I should hit up an Olds forum and see what suggests you all have for getting a little more out of it. I'm in California so I am limited by passing visual inspection and emissions in another two years. What can I do to increase performance and still keep it at least quasi legal?

Also, is it normal to get about 12 mpg with a three speed auto trans? I knew this car wouldn't sip gas, but I figured I'd be getting more around 15-18 mpg.

Here's a pic of the beast:



Thanks!

Brian

 

Was that a California option? I thought they got the Olds 403 or chebby 305.

 

From what I've read the Olds 350 was available in Cali Birds that weren't Trans Ams.

 

depsends on how much you want to spend... off the top of my head, performer intake, headers & dual exhaust with low restriction cats... maybe a cam change...

don't know what to tell ya about the mpg, seems low but that depends on driving style, state of tune and rear gear ratio...

 

I don't think I can legally do headers and true dual exhaust. California makes it tough to do too much on any car made after 1975. I bought a Magnaflow Hi-Flo Cali legal cat. But I was planning on doing cat back dual exhaust system.

My gear ratio should be 2.41:1 if it's stock like I suspect it is. Maybe the carb needs to be adjusted. I don't drive too aggressively and my commute is 85% highway cruising around 65-70 mph.

 

Is it a 2BBL or a 4? If you don't drive agressively like you say you can actually increase gas mileage with a spreadbore 4BBL because the primaries are smaller than a 2BBL carb would be. Make sure everything is in a really good state of tune. How many miles are on it? If you really like the car think about a lower gear and a 4 sp auto to increase performance & fuel economy.

 

Every Olds 350 after 1973 was a 4 bbl with a Q-jet. You are so limited in your options that I think your best bet would be to fine tune the engine and add 4.10 gears and an OD trans. Those would increase driving fun the most, IMO.

As for the engine, your best bet would be to replace the heads with older 350 heads. The smaller chambers will bump up Cr a point, close to 9 to 1. This will allow a cam upgrade. Stock manifolds will be a limiting factor, but externally it will appear stock and still be fun to drive.

 

This car is pretty clean, straight and only has a little bit of rust on the body by the rear window trim. I love the body style of the 77-78 Birds and would like to keep it, but squeeze as much potential out it within the confines of the lame California laws.

Droptopron, it's got a 4 BBL Qjet. I bought a nice fresh one that I haven't installed yet. As far as miles it says 26K, but I'm pretty sure that means 126K, LOL!

Captjim you pretty much nailed what I'm looking for... a fun car to drive. Which heads should I look for and what's the price range for them? As for the transmission what about a built up 2004R? I'm pretty new to working on cars but have some buddies who help me out. Is replacing the stock tranny with one that has OD pretty straight forward?

 

#5, #6, #7, and #7a heads are from 68-72 350s, flow decent, and have a smaller chamber. You will need to drill out the head bolt holes, no biggie. Only die hard Olds guys will recognize the swap.

200 trans swap is not too difficult, the crossmember needs to move rearward and a lock-up switch installed for the converter. However, if you do the engine mods and choose a good cam, you might be fine with the Th-350 and 3.08 gears and still do OK on the highway. My wife had a 77 Supreme with a similat deal, stock engine with #5 heads, 210/216 cam, responsive and fun to drive even with the 2.41s.

 

What's the price range on the heads and where are good places to purchase them?

 

Contact 507Olds, (Brian Trick) He has a couple pairs of heads in the for sale section and he's great to work with.

 

Cool. I just sent him a PM.

 

In addition, check ROP for sale section. There is a couple set of heads out there right now.

 

the 2004R swap is very straightforeward, you don't have to alter the driveshaft or anything too major...
i wonder if you could get by with shorty headers into a 3" y pipe? i would think that as long as it passes they wouldn't be major ball busters about it... then again it is kalifornia...

 

Headers are legal in CA if they have a C.A.R.B. EO number. Otherwise, no. Cat-back exhausts are legal also.

 

I haven't had any luck finding any 50 state legal headers for my Bird. If anyone sees them online somewhere please gimme a shout.

 

Nobody mentioned the Edelbrock Performer 350 intake manifold.

I really don't think it's going to make much of a difference over the stock mani. The saving there would be the weight. A stock iron mani weighs in at 55 lbs where the performer is only 17

 

Where in Cali?

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True duals would be legal if it was an option that year for that model car. Of course you would have to run two catalytic converters... For headers maybe the same year cutlass? You might have to experiment with fit... As long as it has the E.O. number I would think it would be fine. Not sure if the E.O. numbers only apply to specific applications, such as 77 cutlass... I do know that these rules are designed solely to make your life hard.

 

GM never used more than one converter until the late 80's/early 90's on the F body so that idea is out so long as he's in CA.
I don't know that they have any headers for a car of that vintage that have a C.A.R.B. # so he's probably S.O.L. on that one as well.

 

I live in Echo Park, Los Angeles. Some how my friend gets away with true dual exhaust with his 79 Firebird. Dual cats and mufflers. But his car isn't originally from California like mine.

 

Apparently there are lots of headers available for your car... They fit both 77 cutlass and firebird with 350/403. However the only ones I could find on summit with the E.O. number mentioned only the cutlass under applications... Not sure what that would mean for fitment on the firebird. If you're up to it you could always keep the stock exhaust and swap when smog season comes around. Other than that even a nice 3" single would be an improvement over stock even with the manifolds.

 

Yeah, I've found enough that fit, but most aren't going to be legal. Anyway, I'm having my exhaust re-done on Friday. I've got a 50 State Legal Magnaflow Hi-Flow cat and it'll split from there into two Texas TA mufflers and original 77 split tail pipe tips.

If I can score some earlier heads, do you think it's worth spending the money to rebuild this 350? What's the price range a rebuild?

Thanks again!

 

I would look for a 403 personally. They'll never know the difference and you'll have much more fun with the car.

 

Ditto on the 403. Add a hydraulic roller cam, spend some time on a chassis dyno with a wide-band to get it dialed in, and you'll surprise a lot of people!

 

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