Swapping 305 to 350 1984 Chevy Camaro Z28
 

Hi, I'm a new user here on Thirdgen.org, and new to the Camaro pony car. Actually, this is also my first Chevy now that I think about it.. :P Well, I bought this car for $600, only to get it home and realize that I had a rod knock. (I can't get a perfect car that cheap, I know.) So instead of rambling on, I'll cut to the chase; I've been reading that with this 1984 305, (computer controlled carb,) that I can swap a 350 block while having everything from my top end bolt directly on. I was also under the impression that I would be running higher compression if I keep the heads from my 305, (even more so if I ran Vortec heads.) My main concern however, is that my car is computer controlled. Will I need to get a new ECM, or can I run the 305 ECM that's currently in the car? Other than that, I've heard the swap is easy, and pretty cheap. Any information would be greatly appreciated! :) Oh, I know I'll need a 350 knock sensor, but will I need anything else? I'd like to keep the carb computer controlled as it's, from what I've read, better on fuel. If that's not the case, I could go to non-computer controlled.

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

You would need a chip (tune ) from a CC carb 350 engine in your computer

If you go for a reg carb setup similar to this ( without the speedo issue )
https://www.thirdgen.org/forums/elec...-z-28-tpi.html

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

There's no substantial difference between the 305 and 350 chips. The one you have will work "OK" at least. Best thing to do would be to get one out of a L69 car; easiest to find those in a Monte Carlo SS these days.

350 knock sensor, maybe loosen the air valve from its 305 setting of 7/8 turn of tension to a 350 setting of around 5/8 turn; maybe bump the static setting of the dist up a few °s.

You could use the 305 heads, but to get them to work right, you'd need to have 350 sized intake valves put in them. Vortec heads are a good choice but will require a Vortec-specific intake such as this. http://www.summitracing.com/parts/edl-2116

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

So if I wanted to go to a non-computer controlled Carb and an intake to accommodate, what all would I need exactly? I'm looking to do this while spending the least amount possible, and it seems like going to a non-computer controlled carb is going to fit that need. :P

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

You would need a new carb and a new distibutor.

Not sure how adding $600 or whatever those take, to whatever other expenses, will qualify as "least amount possible"? Most of the time the path to "least amount possible" involves re-using as much as you can of what you already have.

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

Sorry I'm a new member and havent yet figured out how to make a thread. I have yet another 305 to 350 swap question that I'm sure you all are sick of. I want to switch the 305 in my 84 Z28 to a 350 from a 79 truck. Well just the block anyways. I plan on using my heads manifold and carb from the 305, its the 4 barrel Rochester, it is not computer controlled. I am not going TBI or computer controlled. Would I have any problems putting these parts on that block, or that block going in the car? My main concern is having to relocate the mounts or something. Any thoughts?

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

FosterK, I am also doin a 305-350 swap and as far as relocating mounts The 305 and 350 are both the same blocks just different cylinder bore size so no motor mounts should need relocating

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

The Intake will work fine. The heads won't like the 350 block though, it's going to shoot your compression through the roof. If you are just going mild, I'd look at getting a Vortec style intake and vortec heads if you're on a budget. ALternatively, you could find a set of L98 heads of any 350 thirdgen and those would work just fine with the intake of your 84.

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

You could use 305 heads on a 350 for increased compression with the right setup, I know I've done it several time on firebirds and camaros but there is always a risk of ruining something with compression that high...if you want to do it I'm sure there's a thread for it

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

I am going back together with it now...my comp. Is about 11.5to1 I bought aluminum heads I have to pick them up from port and Polish tonorrow

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

Good choice but be sure not to torque the head bolts all at once, do it in increments to avoid warping the soft aluminum

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

Yea, I have built a lot of Ford racing engines. Been bout 20 yes since I have did a Chevy though....I forgot how inexpensive these puppy's are. My last was a stroked big block in a foxbody mustang

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

Nothing's better than a chevy small block except the sound of a chevy big block 😏

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

Yea my fords a beast.....I went wayyyyyy over board restoring and building that monster.....my sponsors and I are in that one for way more than I like talking about...but talk about rolling thunder....wife is a Chevy person so I'm building g this for her like I promised... LOL

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

Good man, I am a die hard chevy guy though I do respect some ford engineering. I'm building a 1984 z28 as my first car (I'm 16) I'm putting a 350 in it, it's got a 5 speed and fat drag slicks

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

LOL...I had an 84 5.0 ho Z and traded for a 1986 Iroc that car was a hoot after I got thru playing...new runners new t/b cam rockers and huge full length header 3 inch exhaust into a flowmaster...hell the exhaust was most costly...but before my 175 shot NOS she ran low 12's up at Milan dragwat in Michigan...grew up alittle ways from track

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

Yea mines the HO. Painted red with 3' exhaust haha I also got full length hooker headers, my dad had a 1986 iroc also lol with 5 speed and turd tops also he put a performance chip in it...but my stock 350 has more HP and torque than that already I can't wait to get mine running it's been my dream for years, best part is me going to a technical highschool for automotive I get to do all the work to it myself

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

That's how it is here...my boys and I fabbed the stang from front to back I cut 11.5 inches off the 8.8 I use a true spool kept the street gear 3.73 with a really nice AOD behind it...we have to do a 35 mile street cruise before staging to race

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

When removing the 305 out of my 84' z28 I found the easiest way of doing it was to remove the motor with the transmission attached, it's easier installin it together also because reaching some of the bell housing bolts are near impossible to reach. Just some info I think would be useful

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

Yea...I've got some badass swivel sockets and 4foot extensions

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

Hey vetteoz, what do you know about removing wire harness?..or what part can I remove from my 89 rs? without effecting ignition,lights..etc?

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

Well you have two access points from the driver side sprocket and the passenger side under the dash past your computer, i know it may sound complicated but it's real simple to undo all this.

And this is only for your motor not your lights ect, if you plan to go carb it's a breeze. There is a 7/16 socket on the driver side bulkhead connector it may be a 10mm but you get the point. Take it off and pull the plug on the other side, and it will slide right out, watch the rubber air lock on the passenger side pulling it out from the door jam up to the engine bay though. It's some sticky ****, and it's on the other side too disable vats.

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

Ok Thanks, I am running a carb and the motor is running, however it wants to break down at around 2500rpm..I have a 12v switchable source but not sure as it stays while running..I'm thinking without mas, tps...etc not hooked up its putting the ecm in limph mode..So I may disconnect ecm and try it.

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

Your running a carb, it's not taking on signals other then 12v spark and alt and fuel.

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

Yeah, I'm stumped at this point..I even ran a jumper from batt to coil and still breaking down..Its all new MSD Ready-to-Run distributor, and blaster II coil, 9.5 mm wires. It ran awesome on the stand..I'm thinking maybe something shorted out in distributor.? wanna come to Vermont and take a look?..haha

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

...if the Alt wires are crossed would that make a difference?..its a two prong plus the "BATT" lead.

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

IDK maybe he is running a tbi pump through his carb....you need a Mallory but gas would be spewing everywhere if that was the case.

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

That would make it not charge, not sure but probably cause some other problems as well.

Define "Breaking down"...

Does it do it only under load?

Can you sit with your foot on the gas and hold it at 2500+rpm?

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

also a frequently over looked item grounds make sure ALL grounds are connected and clean check to make sure the ground on back or head is honnected those can case what you experiencing as well

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

Connected damn phones and small keyboards

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

Also if you reverse the fields on the alt (plug wires in wrong) you might cook the regulator as long as you caught it fairly soon you would be OK....long range damage could/would be overcharging you battery (salphating) it which might cause it to explode but that one of those one in a gazillion things more than likely either the alt goes on the Fritz and stops working or you see wetness around battery caps....in which case drive to local autozone/oriellys ask one of those retards to do a charging system check and you will see what's going on

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

I did a voltage test on motor, chassis, distributor..everything grounded good. I tried a different coil and same thing..Going to try a different distributor next. maybe I crossed something when we did the swap.. Thanks guys.

Re: Swapping 305 to 350 1984 Chevy Camaro Z28
 

..oh and the alt was fine.