Hey guys, I've had my '89 firebird for awhile now and looking to start building it up, very slowly (grad students are poor). It has the 305tbi, auto trans, non-posi. The only work so far has been to upgrade a bunch of the suspension parts. I'm thinking of doing the exhaust and minor engine mods, then (a year or so a way) taking care of the body. So my plan is:

new exhaust (I think Flowmaster 80 series)
headers (everyone loves the hooker 2055s)(used due to $$)
intake (suggestions?)
new cam (suggestions?)
Maybe heads at some point in the future. I hope this will wake up the engine but I can do it in steps. I figure all these parts will also bolt up to a bigger block if in the future I lose the 305 (though I'd really love to drop in a Pontiac block eventually, which far as I know won't work with sbc parts). When it comes to choosing engine parts though, what do I need to know for cam and intake choices, I'm overhead when it comes to engines? Any comments are appreciated!
-Mike

ps. I hate all the crap in the engine bay that hides the motor.

 

That's nearly my exact same list.

The only difference is I did the Posi 3.42 swap after suspension. I'd recommend it highly. You can see my posts on it here:

https://www.thirdgen.org/forums/tran...erence-do.html

I'm at headers now. Still deciding.

Also, I did swap in the EBL computer upgrade somewhere in there. I haven't messed with tuning much yet, but it is ready for when I get a new cam/heads.

I'd also recommend that because it gave me a nice professional "scanner" that will also be useable in the future. I really like the dashboard on the EBL, it gives you a lot of feedback quickly while you are driving and it works great to "see" what the engine is doing at all times.

 

do the ultamit TBI mods
youll gain 15-20 hp just from that

 

I am not going to say you have to do this, but will recommend it.
If you can live with the 305 kinda sucks, but you can keep it running, and save for your bigger engine.
Unless your restoring it or just really want to show people what a 305 can actually do, your going to put more money in it then it is worth.
However the headers should swap with no problem to a 350, along with the exhaust.
Just my thought.
Other then that, looks good it you want to do that.
The only thing I would do different, before you get a cam, get a computer you can tune. Play with it before you put any kind of cam or anything in it.
Then when you do, you will be able to tune it easier, and it will take less time to get it "dialed in". In stock form, you can reset to the factory tune and start over.

 

uummm, no you won't.

https://www.thirdgen.org/forums/tbi/...-synopsis.html

Here you go.

If you want a clean engine bay it's going to depend on how far you want to go. I went all the way with mine but I don't have emissions where i live so I can get away with it.

here's what it looks like.

 

Thanks for the feedback, glad to hear my plan makes sense. I know the 305 will never be a monster, but it's what I have so I figure why not play with it till I outgrow it? And like you said, all the mods will bolt up to a larger sbc.
I have never heard of the EBL computer stuff, I'll have to comb around and see what that is.
I must say, that engine bay looks perfect. I wonder if with a cat you would still pass emissions? Though how do you deal with no AC living in Arizona? I used to live in NJ were touching the emissions equipment would be a problem, but now that I moved to NC I've heard they can be pretty lax down here. Also, did you just weld up the AIR fittings on the 2055s?
Last thing, for choosing an intake: I've seen most buildup articles speak highly of the Edelbrock Air Gap, but I know with a carb plate any Holly can work. However, these intakes would prevent use of Vortec heads in the future. Are there other good similar priced heads to consider that won't run into the same complication? Plus will the Air Gap clear a stock power bulge hood?
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so it boils down to Edelbrock for true bolt-on or will some other with the tbi-adapter be better? Or is the difference too small to care?

 

the air gap is not a good upgrade for a TBI vehicle. If you want to change out the intake you have a few options. Edelbrock 3704 TBI intake (which I have) Edelbrock RPM intake ( need an adapter and enlongate the 4 center intake holes ) or any 87+ carb intake with an adapter.

AC for me isn't a big problem. I just roll the windows down. Yes I welded up the AIR fittings.

The 305 can be made to be a strong performer with the right planning and keeping realistic goals. If you want to build it, build it. It's a great learning experience.

 

Here's the site:

http://www.dynamicefi.com/

You'll have to get into tuning one way or another once you do a cam swap. This is just one option. I think it is the most elegant option, though.

 

It seems like it would easier to just go with the manifold designed for the tbi unit. 3 questions though: where did you get the 5.0HO lid? It looks great. Also is that a drop base or non drop base open element base, and where do I get one (Summit I guess?)? Finally, where do you get the nice breather filter I see on the back of the passenger side cylinder heads?
Seeing you engine bay really makes me want to pull off the emissions everything. I read though if you disable the air fittings you need to modify the ecm to not lean the mixture since you will be lacking the added 02 signal? And you removed the EGR and canister too it looks like.

 

I got the h.o lid from a L69 car I worked on awhile back. She gave me the lid after I fixed up her car. I made the air cleaner myself to be a non-drop based cleaner. I took a stock lid,flipped it over and cut a hole in it for the tbi unit. Here's a thread on how I did it.

https://www.thirdgen.org/forums/tbi/...t-do-open.html

I got the little air filter from autozone for like 10 bucks.

You don't need to tune the ECM if you remove the smog pump but you NEED the o2 sensor, there's no getting around it.

I did remove the EGR and CCP canister but to remove the EGR it does need to be tuned out. I got a chip from Tbichips to eliminate it. I got tired of trying to fix the damn thing.

 

ok, what do you think ive gained, i honestly dont know, im going off what other ppl have told me

very clean engine btw!

 

Not a bad idea with the lid conversion. And since it is nondrop there are no clearance issues right?
I noticed you are planning on running the zz4 heads. Since those are aluminum and have 58cc chambers, I've read they have to be milled down to about 53cc. Is having heads milled expensive? I figure if I can find well priced heads and manifold at the same time, I'd do both at once. So it seems any 350 heads for 87+ will fit as long the intake value is no larger than 1.9in right? Also, I've read some heads have to be "worked" to allow 0.5inches of lift? Can all heads have that done to them? I figure if its not too expensive why not just have the stock heads ported? Or would corvette heads or something the world products always flow significantly better, regardless of porting (besides the aluminum weight savings)? Thanks for opinions.

these were what I saw as a reference, would this be a good deal (sight unseen) or would porting other heads be as good: :http://cgi.ebay.com/ebaymotors/ws/eB...n%3D3%26ps%3D5
though the erg stuff has to be plumbed externally until removed later on.

I know this link as flow numbers, but what about porting stock heads:
https://www.thirdgen.org/forums/tbi/...-headflow.html

 

I don't know, but I'd say in the range of maybe 1-3hp. Even with a better flowing TBI, your heads are still the limiting factor in hp (assuming your motor is stock otherwise).

 

getting heads milled is not expensive. Each of the 4 machine shops I've worked at charge less than $50/pair. Ask to have them milled 0.030" maximum.
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And milling should always be done AFTER any porting, in case whomever does the porting has any kind of slip or accident.

 

yes its stock,
it still has the stock air cleaner
my new throtle body is off a 350 so it has the 50 pound injecters

what kind of power does yours put down?

 

Mine is still all stock, so 170hp at the flywheel. After my mod though, 300rwhp is my goal.