Hey there,

I'm considering purchasing a 3rd gen Camaro soon. There's one for sale at a good price and it has the 305 in it. I was wondering if its best to wait and buy one with the 350 in it?

I was reading up and doing my research as far as modding the 305 and found that not much can be done with it compared to the 350. Seems most recommend doing mods to a point and then suggest engine swap to 350 or LS1

I would appreciate any thoughts from the veterans since I'm a total noob. Not looking to mod super crazy but I do notice that the base specs indicate an almost 50 hp difference between the 305 and 350 from factory.

Oh BTW its a 1989 IROC-Z.

Not sure if this is the right place to post but seemed appropriate as its an engine question.

 

A 305 to 350 swap can be accomplished by a blind, one armed man in a wheelchair. Why, even I did it! Seriously, be more concerned about the body/rust situation and whether or not you like the car.

 

I always get "sounds good" comments about my 305 but never that's fast. one of the biggest things with mine (was tbi) is the heads they just don't flow. Mid throttle response isn't too bad but nothing really over 4k. little to no aftermarket 305 parts.I've put an edelbrock carb/intake msd 6al2 programable ignition distributer meth injection headers 6 speed with 3.73's spent alot of time watching the air/fuel gage and tuning the carb/timing curve and I'm a little faster than a stock tpi 350. If you power do an ls swap.

 

If you like automatic transmissions then wait for a 350 Camaro. The only stock way to get a manual transmission in a 3rd Gen is with a 305.

 

305 or 350 it doesn't really matter because you can always do an engine swap from 305 to 350, its been done hundreds of thousands of times. That's waaay less important than body condition. I don't mind having a 305 Because it is MY car whether the next guy likes it or hates that I have the stock 305 in there not that's not for him to say. I had an '87 Iroc 5.0 Carb and while it wasnt very fast I did take up to 110 few times. My "92 Z28 5.7 will go faster but really unless you wanna risk speeding tickets with heavy fines, the 305 with some bolt on mods will suffice, I love my stock 350 but I would still keep my Iroc Stock with the 5.0 and just change the rear gear ratio and add an aftermarket exhaust for better sound & driving. And the '89s & '90 whether 5.0 or 5.7 are harder to find for cheap, & somewhat more sought after.

 

If you're going to be using it as a daily driver, you'd probably appreciate the 305 more, as it's likely to get you a little better gas mileage, if you're going to use it as a weekend cruiser or don't care about mpgs, 350/lt1/lsx swap is a good option, depending on how much of a budget you have. If you're on a small budget or don't want to spend a lot of time prepping the car for the swap, then swap in a decent 350, change your injectors & get a new prom (someone correct me if 89 still had a carb, I can't remember) & enjoy the extra cubes. If you've got a moderate budget and don't mind doing some prep work to the car, then I would suggest considering a LT1, they can be had for cheaper than most LS motors (the 5.3s may be cheaper) and they share a lot of parts with the gen 1 motors and don't need an adapter plate to bolt to your existing transmission or require special motor mounts or headers. Of course, the swap that's going to net you the most horsepower would be a LS swap, but it's also likely to be the most expensive. You would need to get an adapter kit to use your existing transmission, or make sure that the motor you purchase comes with one, you would need special motor mounts since the LS motors have a different location than earlier and you would need headers designed specifically for LS motors as they have a different exhaust port design than earlier, the parts are there now, enough people are doing these swaps that several companies produce the needed parts, just factor in that you would need those beyond what you would need for a regular 350 swap. Also, if doing the LT/LS swap & you want to keep the fuel injection (most would recommend this, but carb intakes are available) you will need a wiring harness (either the original from the motor reworked or an aftermarket) and you will need to get a PCM with the engine (most sellers include them, but some don't) and then you will need to find someone to reprogram it to forget things like VATS & to work with your specific setup.

A good place to look to see just what's involved in a specific swap would be the engine swap sub-forum on these boards. There are a lot of helpful threads & writeups from people who have already done the swaps, that's where I got the majority of the information when I decided to do my LT1 swap, definitely helped me out a ton.

 

Last year I believe was '87 for carbs, my Iroc had the LG4 but in '88 they went to TBI

 

I have a 350tpi and love it. Makes great low end power, ask anyone. When im done with my build, im looking at roughly 350hp (crank) and 450lbs torque. Thats alot of power, and with the tpi setup itll be done at around 6k rpms, which is fine for a streetcar IMO. TPIs can be found for pretty cheap, lt1s are good motors as well but will cost you a little more. It all depends on what you want to do with the car, the lt1 will breath better at higher rpms but the tpi is undeniably the better low end setup.

If you can, ls is of course the best to do. But of course itll cost you more than likely 2-3x what a tpi or lt swap will. Its all personal preference, what are you looking for out of the car?

 

You are correct. You only got your car to 110?

 

Yeah, it was non G92 so I had the 2.73 gears, and it took me about 2 minutes to get to 110, the speedo was buried because it was the '85 mph speedo but I was chasing a friend in a C5 Corvette and he said he was doing 110 when I caught right up to his tail. I'm pretty sure I could have gotten to 120 but I was already at 5000 rpm and running out of road. My 92 Z28 5.7 TPI can get to 110 in 15 some Seconds , but when I get that old Iroc back I'm going to install 3.23s a Flowmaster 80's Catback System, do some carb turning and maybe a Cam upgrade, and a b&m shift kit, just to make it a nicer more responsive cruiser because you never forget your First Camaro and that '87 Iroc was my first, so I wouldn't swap out for a 350 to make more hp just for fun weekends temporarily, unless I kept everything in bubble wrap in the garage to put it back to stock.

 

p.s. as I was writing this, An Earthquake happened here the room shook

 

People here in the office felt it. I didn't lol. Actually I got my LT up to 130 once. Stock 2.73 gears and all on the 605 ages ago. Was surprised it was able to hit that speed.

 

I managed to push my 92 to 105 once when it was still in one piece. With a 2.73 and stock 305 TBI it took a long time & a slightly downhill slope. It did ok until 3rd gear ran out about 95, once it got into 4th it just really didn't have the ***** to move the car that fast in OD.

 

Well at least in "bare bones", the lg4 or lo3 do need a bit of road to get to a nice speed. That we can all agree on.

 

There was a 305 that was only 15 h.p. less at 230 than the 350 at it's 245 h.p. rating.

 

Well, that's not really true. You can do pretty much the same things to a 305 as you can a 350. The only real exception is that you have much more limited options when it comes to heads and valve sizes on a 305... and you ultimately have 45 less cubes to work with.

Coaxing performance from a 305 eventually becomes tricky because the smallish bore limits what heads you can use, how big the valves can be, and the lengths you have to go to to work around those limitations. That said, if you're willing to work with it, or already have a 305 that you want to build for whatever reason, then the 305 can be a fine street motor if you choose your components and build wisely. But the 305 can never be anything near an ideal, high-revving strip engine. It can be made to make good "street" power to around 6000 rpm or so (which is what you really want on the street), but go much beyond that and you run into its bore size limitations.

The 350 isn't limited in that regard, so if you ever intend it to be a high-revving strip engine, then the 350 is an infinitely better choice. Also, if you're starting with a clean slate and just looking for the most horsepower and torque you can get for the least cost (and the "easiest" route to get there because of the many aftermarket options) then the 350 is the clear and obvious choice as well.

Personally, I've built 305's and I've built 350's (even a 305 that could hang with just about any of the street-only 350's), but you have to be aware that the 305 can't hang with the 350 as the revs climb so high (though that isn't really a factor on a street engine) and you have to put much more attention to detail and component choices to get the 305 to respond favourably than you typically do with a 350... and there will always be the 45 less cubes.

That's my anyway.

 

I agree with CaseyButt, its possible to build a powerful 305 of course, but IMO it takes more work and $ and you get less results. Say you put $100 into your 305 and gained 100hp over stock (completely random numbers), but if you put that money and even some of the exact same parts onto a 350, you gain more and the difference is more noticeable. Ive driven in a car with a 305 carb'd that was slightly built (mainly bolt-ons) and told myself id never own one. Its no-where near as torquey as my 350 and as of now the 350 is basically stock (k&ns, msd coil,gutted airbox, de-screened maf, thats about it right now.)

I am in no way trying to talk you OUT of using the 305. I just want you to be fully aware of the difference. They put 350s in the top-of-the-line fbodys for a reason- they're the best. But as mentioned, you can build a respectable 305 street motor too. It really depends on what you want to get out of it. My goal for my tpi350 is low-mid range power, done by 6k rpms. Tpi runs out of breath by then, so i want all my power to be before 6k. Itll have gobs of low end power, crazy low end and mid range torque. Thats just what I want. You may want a higher revving engine, and as stated by Casey, the 350 is still the better option in that aspect as well.

What are you hoping to do with this car?

 

It was a 4.1 magnitude epicenter in Yorba Linda, and I took my '87 on the 101 Hollywood FWY, and my '92 on the 60 passing the 605 crossover got off the exit where the Fry's electronics is made a U turn and got right back on the FWY doing 112 going back.