Im looking to swap out the stock 305 for a 350 (what I have seen to be a common and "fairly simple" swap). But i noticed the 383 becoming more popular around my area and wanted to know what the differences would be in a 383 swap (money, time, etc). Im in a '90 Camaro RS and want to get the motor to around 400-450Hp (if time and money permits). Is either one or the other "easier" to get it to my needs? Less expensive? Less mods? Thanks for the help this is my first real build.

 

Are you building the engine or buying it complete?If rebuilding the 350 & you need a rotating assembly,then the 383 won't be that much more expensive,other than machine work to the block.If your crank is good,build the 350.If buying the engine complete,get the 383.Using comparable parts,the 383 will have approx a 20 HP gain & as much as 40 to 50 ft/lb of torque.The 383 will respond to other mods better than the same mods on a 350.It's best to make up your mind before you buy parts,especially cam & heads becuz the optimum cam & heads for 350 won't be the same for a 383.The 383 can utilize & a larger head in the intake ports vs a 350.Slightly larger chambers to keep CR in ck so you can use a decent piston instead of some circular dish.The 383 will also benefit from larger cam.

 

Awesome that's very helpful. And I do plan to rebuild/upgrade everything in the engine. As far as the actuall swap, what modifications would I have to make? Or would it be the same swap as a 350 swap? This was what I was most concerned with. I don't want to buy the 383, build it all up then find out I have to change a ton of stuff just to get it in. Great advice though for the 383 you got me leaning that way now haha

 

You can rebuild/pick all the parts for your new engine, have it all shipped to your house without any problems....choose a machine shop to measure and assemble all the parts,..then swap it into your car, ditch the efi for a carburator to ease tuning, etc...

Or you can buy a RamJet 350 for $5,000+ shipping.. Install it, supply 12 volts and 45psi fuel pressure. It's EFI, already tuned, makes great power for a thirdgen.. And will get good gas mileage, great cold starts,etc... And it has a warranty I believe...

It's a big commitment for an "old" car but it is the ONLY way I see to add value to these old cars. Your typical 350 build doesnt really add value to a car because even receipts can not prove what is inside the engine... A Ramjet 350 is unique looking and the receipt alongside it adds real value.

Put a Holley Walbro 255lph fuel pump in the gas tank is all you need to feed this crate engine properly..


Goodluck, welcome to carmoneypit.org... Hahaha

 

I knew it was a money put when I started but that's part of the fun haha. Well thanks I'll definitely look into that and see what I can do.

 

Everything between the Small Block Chevys will bolt up, whether 305, 350, 383. Engine mounts, transmission, exhaust, accessories, etc.

* your 305 has a 1-piece rear main seal (RMS). If/when you get a replacement, you will need a different flexplate ($50) if the engine/crank is an old (pre-86 or 87?) style 2-piece RMS.
* the exhaust that was maybe sufficient for the stock 195hp-ish TBI 305 will be a restriction for anything with more HP. In order to reach 400+ hp, plan on eventually replacing the entire exhaust. The factory exhaust WILL work as-is, until you save funds to upgrade the exhaust, but it WILL be a restriction.
* stepping up from a TBI to any direct port would be nice, but requires a new fuel pump (15psi for TBI to 43-ish psi), wiring, ECM, etc. Keeping TBI requires bigger injectors.
* TPI, while a stock option, will be a restriction to RPM and HP. A RamJet crate engine could provide an all-in-one solution. The Weiand Stealth Ram (used to be Holley SR) is a popular TPI replacement. This could be your intake to go along with everything else from a TPI engine (wiring, injectors, ECM, etc).

 

Im not a big fan of crate motors in terms of what you get for your money not being exactly what YOU personally would get... but in the sense of resale value, a nice crate engine is going to be the ONLY way to add value to these cars, and Im not talking about any goodwrench 350 or even Random Local Machine Shop Special. You want a big name like GMPP backing up your crate engine. You are EXACTLY right on that.

Custom-built engines do NOT add value to these cars and often do a lot to cobble up an otherwise practical factory setup. At least with a GM crate a lot of the weird experimental areas are already matched so that leaves less things for you to have to address and figure out by the time you get to actually drive it around.

A $3500 ramjet 350 wont add $3500 to the value of the car, but I'd say it would add maybe $1500-$2000 if you kept receipts and the swap was clean and the car drives like a factory stock car. The execution is EVERYTHING when selling a car with a swapped engine. If it drives the way the factory would have it drive, you can actually see some value increase in the car. If it's temperamental (Even if fast) you are not going to see any increase in value.

Do not swap ANY 2 pc RMS 350 into your car. Those things are old and dont have the modern perks of newer blocks. Roller cams and less bore wear due to accurate fueling is a big deal.

If you end up, like most of us, building your own custom setup, you can do pretty well for yourself, you just cant prove it. 383 vs 350 depends on your budget, but I will say this, the top end is what makes power. The bottom end, all else being the same, does not. If you go with more cubic inches you will make more torque, but not more horsepower. The RPM range will shift down, and you see this in the way people often spec out larger cams and heads for 383's. The other way to look at it, is when you increase torque production, you can shift the power band higher to make more horsepower and still maintain the level of low end torque you want even though it may be less as a percentage of the peak torque the engine makes than it would have been otherwise.

It's kind of hard to explain this well, but basically if you go 383, the only way to make more power out of it is if you use the extra cubic inches to your advantage and spec out bigger cams and heads with larger ports that will take advantage of the extra torque you're making and push that torque to higher RPMs. Remember, horsepower = RPM x Torque. If you make 350 lb ft at 2000 RPM, if you can shift that 350 lb ft to 4000 RPM you will double the amount of horsepower you make, but with the way these engines work, you are limited in how wide your power band can be, so you make low end torque sacrifices to hit the power numbers. Larger displacement lets you claw some of that back.

 

If your current 350 is going to need the typical machine work such as boring, honing, decking, etc. the best bang for your buck might be buying a 383 block from summit. For $700 That block is already clearanced for a 3.75" crank and all the machine work is already done which depending on your local machine shop prices is a better deal. From there buying an eagle or scat complete rotating assembly will have your short block set up for less than $1500 provided you can assemble it yourself.

 

Well now that I know all the above I'll probably go with the 350. Like the thought of the (traditional swap/build) for my first real build. Earn my stripes haha. I really appreciate all the feedback and information. I'm just a sponge soaking up knowledge. Many thanks.

 

The MEFI4 controller that comes with the Ramjet is a piece of crappy & is locked.Very few can access it for proper tuning.If going that route,you will be much better off to use an 0411 controller or even the Vortec black box for controling engine.The Ramjet controller also can't control transmissions.It's actually made for marine use in boats with an altered tune.

 

Go with a 383. For the HP you want to attain, you will have to get more fuel, air, and exhaust thru that engine. At that point you will be replacing the same things either way, so you can actually gain on the 383 for what you spend. Plus, have you heard a 383 next to a 350? If I was looking for a 3rd Gen and found 2, one with the 350 and one with the 383, all else equal, I know what I would pick, but that's just my $.02. I'm in the process as we speak of swapping a 305tpi out for a 383 right now!