So, due to my ever-annoying intake gasket leak, combined with the fact that the engine is obviously pretty weak, I've decided I want to have the engine pulled and rebuilt next spring. Don't try to talk me out of the 305, or the TBI...both will be re-used. I'm not doing this myself, so the easier I make it for a shop, the less expensive and easier this will be.

With that said, what I'd like to do is the following...

1) Rebuild bottom end, boring .030 over if needed. Stock 9.3:1 pistons seem to make sense to me...forged, IMO, would be overkill for this engine.

2) Add an LT1 camshaft and Vortec heads, along with the required GMPP Vortec intake. I assume I need an adapter to make this work with TBI?

3) Add Edelbrock TES headers and y pipe to my existing Magnaflow cat and catback...

So now, the big questions...

1) I have read the tuning boards extensively...I am still completely lost, and afraid I will burn a valve or wreck the cat tuning the fuel curve, or do something worse. I'm sticking with GM parts for hopefully solid reliability, emissions and maybe tunability? Vortec intakes do not have EGR, correct? I assume this may not be emissions compliant then?

2) Does anyone know of anyone in the MA area that can tune this car for me?

3) If I get it tuned right, what kind of FWHP can I expect out of it? Is 250 out of the question? Its a pretty light build, with mild bolt ons and a pretty basic cam and heads...

Basically, I want more power out of the car while not making it a drag strip terror. I want to retain the 305 because a) its what the car came with and b) I could pull the 305 like everyone else and throw in a 350, but then to me its less unique and even more items have to be changed...

I'd like to maintain decent highway MPG (longer term plans call for replacing the T-5/3.08s with a T-56/3.42 combo), ok emissions and respectable power. Am I on the right track? What am I missing here, besides the ability to tune it all? I really appreciate any help anyone can give me.

 

I know you don't want talked out of the 305, but let me make a couple quick points and I'll move on.

It is much more expensive to rebuild a 305 than a 350. The cost difference will pay for a rebuildable 350 long block. Plus you can be driving the car while you build the 350. I would even buy a 305 block and rebuild it just to avoid the down time and storage fee's.

You'll still need a chip, which you need anyway for the other mods. Then all you have to get is a set of injectors, which need upgraded anyway and a knock sensor.

My point is for about an aditional 50-100$ you gain 30-50 HP. You just won't make that much power for your dollar any other way.

On to your other questions,

1. forged pistons are not needed

2. This is a good combo of parts but the GMPP intake is pretty tall and will be ultra tight to get a 3" filter under the hood.

3. The edelbrock's will work but have a very small primary pipe as well as a small y-pipe. You can get the headman's for less money with the air attachments and they'll flow better to boot.

4. Tuning isn't easy, but it's way better than a mail order tune. Finding some one local to tune your car is an option but you're paying for a single tune and any modifications you make will require a re-tune. Some shops charge upwards of 300-400$ for a dyno tune. This will pay for the equipment 2 or 3 times over. Check out my "free tune" sticky and see if that helps you understand any better.

With the above parts on a 305 you can expect 260-270 flywheel HP and around 230-240 at the wheels. The same parts on a 350 will make ~300-310 and about 270-280 at the wheels. The 350 will push you into the high 13's and possibly into the 12's with a bigger cam. The 305 will get you mid to low 14's.

Just guessing but I say 26-28 mpg on the 305 is possible and probably between 25 and 27 for the 350 on the highway.


You need to look at your emisions laws carefully, do you have a sniffer? Just a visual? How strict are the inspection stations? Some won't even pass you with an open element air cleaner while others just check to make sure you the charcoal canister and cat. GM does make a vortec intake with mounting provisions for an egr valve, it requires external plumbing to make it work, but simply having it on the intake will suffice for the visuual and you won't need it functional to pass a sniffer.

 

I sincerely appreciate the info and the response...the reason I was tough on the 350 idea is because I don't want a ton of "a 305 is a boat anchor, why would you want to do that" responses...you gave me exactly the info I needed, and I appreciate it.

I have definitely considered just doing a GMPP crate 350...that way everything is new and has a warranty. But, I kind of like the idea of rebuilding the existing engine because it kind of maintains an originality to the car in a way. I'm more of a restoration type than the type that requires all-out performance...I have my Z28 when I feel like hauling With that said, if I'm giving up 40hp or so (which is about what I figured) and spending as much as a 350, then obviously there are some things to think about...hence why I've started researching this long before it will be done.

Having the car down for a month or so is not a big deal...this is not my DD, as I have a demo through work. It was just in the body shop being completely redone, and looks gorgeous...it just needs a little more ooomph

One question...I have a 1" drop base Edelbrock elite air cleaner with a 14x3 filter in it right now...will that be sufficient to get that GMPP intake to clear? I've already thought of that...

As for the emissions, I MAY not have to pass anymore starting next year...believe it or not, the ****-Emissions capital of the Northeast (we have the same laws as CA at this point) should be exempting all '95 and older vehicles starting in 2008...no one knows for sure yet. With that said, would it be wiser to keep the Edelbrock TBI Intake I just bought, and find heads to go with that? I assume the Edelbrock heads meant for a 350 won't work with this engine???

Again, any and all insight is appreciated...this is my first time building an engine!

 

a few comments:

350 heads won't work on a 305.(they can, but it can be involved, and for this build, unnecessary.)

I agree on the forged pistons being overkill, but investing in a forged crank would probably be well worth it, especially when you've got such a long stroke built for such high rev's.

if you want to go non vortec, i think dart makes some good ol' fashioned heads that flow quite nicely, though if I remember correctly, they're a bit expensive.

if you're not going vortec though, and you're not looking for ZAAANNYY power or whatnot, just port the stock heads, change the valves. then you've got a more stock looking engine, more flow(though nothing record breaking), and you'll save a fairly large sum of money.

in fact, if i remember correctly, you have to change the valve springs when you do an lt1 cam change anyway, so depending on what head you choose, and partial head rebuild is most likely in order regardless.

which brings me to the next statement, check the valve springs on whatever heads you buy(if they come with any) and make sure they're properly suited for an lt1 cam!

also, if anything happens with your fuel, it'll be running lean very lean at first with that kind of mix. with tuning you might be able to pull enough out of it, but you might need larger injectors(if not a better fuel pump), you're talking about 100 extra hp here(not to mention increasing your redline to 5500ish).

oh, and one last thing. if you're going for 3.42's, why not go for 3.73's(or hell, 4.11s)? on an automatic you'd notice a difference, but on a 5 or 6 speed the final drive ratio difference is almost nothing at all, whereas first gear will be much more fun! it'd also help get that small bore 305 ball rolling.

http://www.zracer.com/camaro/gear_ratios.htm

comparatively, an auto with 3.42's final drive ratio is something like 2.39, and 2.26 with 3.23 gears.