i have been doing some research this week to decide what type of mod i am going to put in my 305. i just finished saving up my money and enough money for quite a few mods if i wanted to. but i always here people saying just put in a 350, but i can add stuff to my engine such as headers, exhaust, heads, cam, intake, ignition, and more that would definitely get my HP up and even putting in a chip i can get 25% more HP. so do i do all the modifications or put in a 350, because couldn't i do enough mods to get my 305 as much HP as a 350? but i sounds like a 350 would be more expensive? i dont know what to do?!

 

you can mod a 305 to about 350 crank horsepower n/a then throw a turbo or power adder of your choice for another 100-200 hp . it all depends on what you want ...

 

that's what im sayin, i really dont know, but i think i would wanna get 300 HP or more out of my 305. but i was planning on putting in a few mods but all roads lead back to me just putting in a 350. would it be more fuel efficient to go with some mods and then a turbo compared to a 350. and what are the cost of some good turbo?

 

thats my plan actually , i'm gonna put vortec heads a lt1 cam i'm gonna get the dynamic efi computer to tune with add headers then once thats all tuned to the max i got a turbo in the basement i'm gonna add to the mix i'm wanting low 12's out of mine ...
a 350 or 355 or 383 may be cheaper but i like being the underdog an the 305 is that lol . plus as far as i know i'll have the only turbo'd third gen. in my area .lol

 

thats why i hesitant to swap in a 350 b/c if i keep my 305 and build it up, it will be a sleeper, and i want to be able to smoke guys that got a 350.
so your saying a 350 would be cheaper, but would you get more power from the 350 compared to the built 305? and even without turbo, putting in all those mods, would that be a waste of money? and have you done any mods to your 305 yet?

 

First off, just because you have a built up 305 doesnt mean you will smoke every guy with a 350. If you think thats the case, I'll race you.

Second, there is a lot involved in putting a turbo on. You dont just bolt it up and thats it.

Third, if you want lots of power, dont worry about gas mileage. I'm lucky. My engine makes probably around 450 or so horse and I can average about 15 mpg city if I drive easy.

Fourth, price is very hard to estimate. You could either one cheap or drop a ton of cash on either one. As a general rule though, to get the same power out of a 305 instead of a 350 will cost more.

 

mod for mod a 350 will be a stronger engine jus cause it has more cubic inches . i have headers an the lt1 cam an the tuirbo stuff in the basement . i haven't done anything yet i jus been buying parts . my build hinges on the computer i can tune it all with . i'm gonna get that soon hopefully an figure out how to tune it on a stock motor first then hopefully i'll have the parts for the top end . i'm in no hurry myself i figure by the fall of this year i'll have it all done .mine is an everyday day driver so i have to plan my build in small sections .lol

 

lucky for me i have turbo experience jus have to learn the computer i'm buying but rbob offers lots of support so i'm not worried about that either .lol

 

ok you misunderstood me when i said i would want to be able to smoke guys wit a 350 w/ a built up 305. i said i want to be able to, not i CAN smoke 350's and my 305 barley has any mods on it right now.

but basically your saying that to get the 350 power out of a 305 it would be more expensive, and im just better off dropping in a 350 then do some mods to the 350, right?

 

What I was really trying to say was that, what is your definition of 350 power? My brothers 95 C1500 came with a 350 stock making 210 horse. My 350 is make around 450. There is no set amount of power a 350 makes. Even in stock form some are more powerful than others.

Even if you build up a 305 (unless its very built and under boost), I wouldnt sweat racing you. The 305 has some limiting factors based on the bore vs. stroke ratio that limit its abilitly to make good power, unlike the Ford 5.0

If your just wanting 300 horse, a very mild built 350 would be the way I would go. If you want that out of a 305, your going to need good heads. You can get 300 horse out of a 350 with stock heads that are just cleaned up.

 

well would you personally swap for a 350? so buying a new set of heads, plus a bigger block bore somewhere down the line of the mods, i wouldnt get as much power out of a 350 with clean heads and with a few mods. but overall it sounds like the 350 would be cheaper, and i would get more power out of it.

 

and for right now until i get a 350, im probably just going to work on the looks of my car, rims, hood, interior, etc...

 

305 350 383 look identical

 

I'd go with a 350, 305s are only good as boat anchors. I plan on doing a 350 swap as soon as I can save enough money.

 

^^Thats what I was about to say, my 383 is a sleeper Forget hedders unless your doing it yourself or are in fact pulling your motor out to swap(IMO its not worth the labor and cost for the small hp you get) just my

 

The chip programming is what you need to consider before making a decision. If you don't know how, can't afford the time with car not running for weeks/months to learn, and don't have faith in anyone to do it for you locally (I say locally because through the mail, it'll take forever), then you need to pass on modding a 305 TBI.

The issue comes in with the TBI chip having limited capabilities, and bery few folks anywhere that even program TPI chips let alone TBI chips. There's a very fine line with TBI mods before you cross the line into custom programming land. You can do exhaust, small cam like a LT1 cam, maybe better intake - but touch the heads and you've crossed the line, and the TBI heads are the biggest restriction.

Now, a possible option would be a 350 TBI - not hard to do. You need the 350 motor, a 350 TBI prom chip from a truck or Caprice that had a 350 TBI in it, a 350 TBI knock sensor, and 350 TBI injectors - that is a realistic possibility MAYBE - I see you are in Cali, so your inspections process really screws you on much of anything since you have to replace your engine with one at least as new.

I suggest moving

 

i know that, i meant my car would be, not the engine! b/c every one thinks my car is a v-6

 

what do you mean the heads are the biggest restriction? b/c i was suggested to get new heads for an increase in performance. and a bigger block bore? so besides using a chip, all the other mods i can do such as, headers, exhaust, cams, intake, cold air, and others(any other ones that i cant think of right now) whats a ball park figure on the HP i can get out of my 305?
and plus, wont getting a 350 TBI w/ all the other required parts cost more than building up my 305?

 

dynamic efi is the answer to the tuning problems ...

 

The best tuning device, plug play, for his TBI system http://dynamicefi.com/

 

Being in California, can we assume you need to go through smog inspection and test? If so, that will be your #1 issue. For instance, is that Dynamic EFI C.A.R.B. approved?

It can be argued that for a relatively small budget, you can end up with more power out of the 305 than you could swapping in a 350. The reasons for that are, anything you spend on the 305 you'd also have to spend on the 350, and most likely the 350 will need a rebuild on top of that.

But, the more money you spend, the less that will be true, and at some point the 350 will make a lot more power than the 305 can.

Understand that Vortec heads do not have the exhaust crossover passage that your 3rd gen heads use to feed the EGR valve. If you have to pass smog inspection/test, you need a functioning EGR vale.

 

if i was considering an ls1 swap such as this one:
http://sfbay.craigslist.org/eby/pts/2273038381.html

what else would i need to swap it in to my car, and im no engine expert, but is there a way you can tell if there is something wrong with it before purchasing it?

 

You can do a compression check to see if it has good compression that is even across all of the cylinders.

You would need a transmission (obviously - trying to use your current transmission would not be a good idea), a fuel tank from a 4th gen LS1 f-body (which causes problems with the fuel gauge), aftermarket swap engine and transmission mounts, and would need to do some rewiring and have some exhaust work done. Doesn't look like he's including exhaust manifolds, so you'd have to find them or use emissions-legal headers.

 

hmm sounds like some work. what would be the difference of swapping a 350 tpi? can i still use my transmission, and what else would need to be done? a good example would be:
http://sfbay.craigslist.org/eby/pts/2273043525.html