i have an 84 camaro z28 with a 305 ..everything seems to be stock...the current carb is a stock 4bbl..adn im thinking of changing it to a higher performance carb. which carb would be the best for my engine? does the carb also depend on how much horsepower the engine makes? and how much hp does a stock 305 make?....if ne1 answers, thanx

 

edelbrock 600cfm

 

hp is a little under 150. i am not sure on a stock engine if a carb swap would help that much if any. i have been here a little while and read a lot of the posts about swaps and asked about it myself, and seems to me for a bout 300 bucks u would do a hell of a lot better getting a cam and then saving to get complete exhaust, headers, and catback or just straight pipes, which i hope to do soon. after those mods and an intake manifold i think a bigger carb would be better suited. most likely with a stock engine u would have to down jet a good bit, do what you may but i think the money could be better spent.

Also welcome to the boards

 

so headers wud be the better buy..ok..so wats the best kinda headers for my car?..id try to figure it out myself but theres just too many choices and this is my 1st car so im kinda new to all this.

 

you will hear a hundred different opinions on headers.... many will say headman, many hooker, some edelbrock, i personally am considering the shorty hookers.... but if u are looking to spend 300 bucks, i would wait till u got about 600, depending on how long that would take and buy headers, cam, and u might have enough for a catback, and if not go to a muffler shop around u and get straight pipes.

 

Don't do it.

The carb that's there is just fine to at least 260 or 265 HP at the crank, which is what my 305 measures on the dyno with the stock carb, intake manifold, & distributor, and every single emissions device on the car installed and operaing correctly. My car passed California emissions inspection and then a few miles later went to the dyno and generated those numbers.

If you change the carb, you will also have to change the distributor to a non-computerized one.

The way to make a car faster isn't to unbolt the easy-to-get-to stuff up on top that you can see every time you open the hood and looks glamorous. That is the direct path to an unreliable car that costs a fortune to drive and maintain, as well as expensive from spending money on supposedly high-performance parts that don't do anything. The correct approach is to figure out what you current setup's limiting factors are, and eliminate the limits one at a time, with carefully targeted parts. Most of the right parts will be invisible, certainly not all chrome and sexy.

I'm going to assume for the moment that you have the LG4 305, which is the base model V8 for that car. If it's a HO, then the engine is the L69 305, which is a better base to begin from; but most of the same advice applies to either.

The first thing that limits the LG4's power is its exhaust. Get rid of every single piece of it, from the heads all the way back to the street; and replace it with chassis-specific headers, cat, & cat-back, but for some other vehicle such as a 89 TPI 350. DO NOT get ANY piece whatsoever that is compatible with your current exhaust!!!! Doing so will retain the bottleneck in it, which is its 2¼" Y-pipe. Basically your exhaust is about the size of a drinking straw as far back as the cat; so the manifolds, Y-pipe, cat, intermediate pipe, muffler, & tailpipes all should be replaced as a unit, all at once.

THen get a cam. You have the most pitiful excuse for a cam that GM has ever tried to trick the public with. It's even less than the one that caused 70s 350s to put out only 170 or 180 HP. A good choice is the Comp XE256 or at most XE262, with matching springs and lifters and timing set.

Those 2 mods should net you a good 50 HP, probably more.

The next thing will be the heads. You can get a good bang for the buck out of porting your existing ones, or you can get a pair of S/R Torquers. Either way, there's another 30 to 40 HP.

The next limit is the compression. Unfortunately you have dished pistons, so the only way to fix that one is to completely rebuild the motor. You probably don't want to go there right this minute I'm guessing.

After all that is done, you'll benefit from a set of decent gears such as what the HO cars came with, 3.73s. You'll be having traction problems, so you'll need some suspension work. Remember, all the power in the world won't make you car go faster if all it does is sit there and spin the tires. You have no idea how many people I've waxed on the street because they went up in smoke, while my car hooked up and launched. Once you get the car to hook up, a higher stall converter will allow the engine to rev up higher at a dead stop, so the engine is into its power band quicker when it leaves.

All of that except for the headers is stuff you can't see. Resist the temptation to just start swapping the easy, highly visible stuff like the carb, it will do absolutely nothing for you, might even slow you down. Unless of course you enjoy losing weight at the wallet.

OBTW - My car is a 83 HO Z28 5-speed; the only significant changes to the motor are a Comp XM264HR-12 hydraulic roller cam, a set of 1.6 rockers, a set of lovingly worked-over old double-hump heads, and the Edelbrock TES. I still have a cat and the stock L69 I-pipe which is a whole lot larger to begin with that the LG4 one. I can guarantee you, headers, exhaust, a cam, and heads will light up a 305.

 

i agree all the way up to this point, while i agree heads would be good, i think he should get a intake manifold first, b/c if he has the stock manifold and new heads, the heads are going to be rather useless..... for the fact that they aren't getting enough air. headers and exhaust and cam maybe 50hp if u are lucky, depends on how strict emissions are. also i would go for an open element intake, those seem to work the best, the exhaust and cam and intake components all together will easily give u 50 hp if not more, then u will have enough air moving to ur heads to get new ones or port and polish yours. gears wont hurt either but 3.73's IMHO are rediculous(well not rediculous) but not good if it's ur daily driver. 3.43's would be better, for gas mileage, unless u dont care about it. and yeah the suspension never hurts, get some lowering springs and some adjustable shocks.

 

Actually, the stock 305 4bbl intake is sufficient until everything else is done. Then a Performer or equivelent will add about 20 hp at higher rpms.

 

so you think porting his heads or buying new heads that flow probably 20+% more is fine on a stock manifold, personally i think ur full of it, but u may be right, big maybe. i also find it a more desirable mod, we will give it a very underrated estimate of 15 hp, for what 150-175 bucks. that's what about 11.75 a pony.. now heads range from 750-over 1500. we will say he goes with AFR's for 1000-easily over 1100, and adds at most IMHO 50 hp, use a calculator and say 1000/50 that gives u 20 dollars per pony, that's 5 bucks more a pony for only maybe 35 more hp, if all u get is 15 and at most 50 would be from heads.... i would go with intake manifold first

 

Naw, do your own heads! That's what REAL men do

 

ok so lets say he does his own heads, not a bad idea IMHO either, but then lets say GM for once in the entire company's history got somethin exactly right... the intake manifold and heads flow the exact same amount, i know it's crazy but you know just for the sake of saying, then you would be choking the heads u just spent hours even days on... would a head and intake combo, same time install deal be good, i think so, i think that would be the best IMHO.

 

Once the heads are done there is no longer any reason to hold back on the extra ponies the Performer will give you.

It is no big deal. I'm getting my heads back from the shop on Monday but I've had the Edelbrock intake on it for the last year.

 

Well said! Finally GM got the intake right ....and aluminum to boot. Just give'er a good sandblasting and it'll look nicer.

 

My 305 only had an iron intake, and heavy sucker at that