You are not going to be able to change the cam or heads without tuning the ECM. Tuning is VERY important when using TBI!

I would suggest you get a very mild cam if you decide to switch cams, otherwise tuning can be difficult.

Headers & 3in exhaust are a must! Be sure to get a high flow cat or use a straight pipe, a lot of olds cats are clogged up. Beware of Flowmaster mufflers-if you really love the sound then its probably worth it, but they produce a lot of unwanted backpressure.

A set of moderate heads, like vortec or fastburn seem to work well with TBI, but you will need a different manifold. And do NOT waste $$$ on a TBI manifold (Like I did), buy a single plane carb manifold and an adapter plate.

I assume you are talking about a 305 so a new TBI isn't really necessary but would make it easier to reach 300hp. You could probably get by with ultimate TBI mods and a non-drop open element (get rid of the spacer ring).

One thing you absolutely WILL need is a new fuel pump (like a Walbro 150), an adjustable fuel pressure regulator and larger injectors. 300 Hp is not going to cut it with the fuel system you have.

 

 

.435 I, .460 E Lift
Duration @ .050 212 I, 222 E

Pretty mild, but 12mpg is NOT a problem.

I've run this cam in a 5.7L with TBI, put out over 350HP and averages 15mpg-city.

 

 

There is way more to making a 300hp/300lbs/ft 305 TBI car, than just picking a few parts. Trust me on this. I am only at about the 280hp mark.

The cam and heads that you pick, are going to be a major part. But the key will be in the tune. My car WILL NOT even start, with a stock chip in the car. You will HAVE to custom tune a combination that will make those kind of numbers.

I would suggest vortecs, or ported non SP heads. Cam wise, you are going to need to be in the 212*-215* intake duration, and shoot for about .500" lift.

You will also need larger injectors. The stockers are not capable of feeding that much power.

That doesn't even touch all of the other things that are needed. Most people don't realise just how much money I have into my car, not counting the engine.

The people on the board who have 300hp 305's will tell you, it is not as easy of a task, and you might think.

 

 

That is where practice and experiance come in.

You either need to build the motor, peice by peice, and tune as you change each part. Or you need to practice, and understand what changes are being made. So that when you do a new motor, you are able to make the changes needed to get it to run.

I would suggest starting with your stock motor, and doing a chip for that. Then making small changes, like headers, and an intake. Then see the changes that needs.

Once you are confident in being able to tune the computer, then taking on a project like a motor with heads and a cam, will be much easier.

 

 

That adapter plate is designed for a larger bore TB, btu will work.
As for the fuel pump, you can find a Walbro way cheaper on eBay, and you shouldn't need the 255.
Also, there is a way to make a stock Fuel Pressure Reg. adjsutable, or you can buy a kit from Top Down Solutions.

Just trying to save you a couple $.

 

 

If you only have $2000 than hold off on a cam swap. $2000 is just enough for a full exhaust, and chip work. You will then have some coin left to upgrade your suspension. I would do gears and add a posi before you swap cams. A camswap is more than just the cam itself. There is about another $200 of hidden cost. I would stick with the stock heads for now and maybe look into an LT1 cam to get started. When you get confident at chip work you can step up your combo.

Dewey is right about how much it costs for 300hp. When you do it your first time it always costs more than what you think it should.

 

I suggest vortec or ported swirl port heads, although ported non-swirl ports will do the job well too with less fuel mileage and torque.

300 HP is not easy from a 305 TBI. I was able to make 300 RWHP from one. It took ALOT of time, especially in the calibration of the ECM. I would not consider the cam for a reliable daily driver as it lacks alot of torque and peak torque was occuring at 4,500 rpm, peak HP at 6,100. 1 7/8" x 3" headers were not helping, nor was the performer RPM intake and 454 TBI. It would scream though. 15.20s @ 95ish 1/4s in a 5,300 lbs brick.

 

Ouch always thought I could get my 305 down to atleast mid 14's...
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BTW, that is low 13s/high 12s with traction in a F-body!!! It was pulling this to 15.20s!

 

So that setup could easily do 13's what your saying?

 

This is a fairly bold claim you're making. I know you've been through quite a few well setup combinations, but I have trouble taking this as gospel. I can see if you're talking on a 240 hp engine, but at the level that ported non-swirl ports come into play, somewhere around the 400 hp range, I'd assume that the swirl port heads are completely worthless by then. Just seems to me like apples to oranges. Low end torque is overrated IMO. I guess what I'm trying to say is that by the time you need to ditch the swirl's in favor of a good flowing non-swirl port head, you won't miss the small decrease in low end torque because of all the power made up top. I.E. Ported L98's (~260/210 cfm @.500) can make somewhere in the 450-500 hp range, and although you may be a little lower on torque than if you were to use ported S.P.'s (225/215@ .500) but it really wouldn't matter since you'd be making much more top end power.