is a 383 a direct replacement for a 305? I have a 305 and i dont like the lack of power. if that is not a direct replacement then is a 355 easy to swap in. i found one that i thought might be a pretty good deal. is the 383 a lot better then the 355. any help would be appreciated.

 

they're all the same size block so they will all bolt right in. now tuning the car to run with that motor is something different entirely. you'd need headers, exhaust, etc to realize the full potential of that swap. not to mention whatever induction you're using, especially fuel injection would need a lot of work to calibrate it. i'd do some poking around there boards to read some of the forums to understand better what you're planning on doing.

 

the car is an 85 berlinetta and it is carbureted so if i want to do the swap would the only concerns that i would have be the tranny and the rear end. Or is the motor a lot heavier and i would have to replace the front springs too?

 

Blakcamaro-

I am building a 383 right now. Here's a few things to expect:

You are really bolting in a 350 (the parts that make it a 383 are all in the internal rotating assembly), so the conversion should be seen as a 305 to a 350. There's no real weight difference to speak of (outside of general weight differences in the various components).

As far as performance, a 383 is a fantastic way to get good torque (if it's built right). This is because of the longer throw (stroke) of a 383 vs. a 350. Torque is what gets the car moving (especially from a standing stop). A Camaro is a lot of car to get moving, so a strong 383 really adds to the enjoyment.

You must be prepared, however, to bulk-up the components from the engine back to the wheels. The additional torque will rip apart weaker components, including the transmission, driveshaft and rear end. This is especially true if you plan to do any racing/hard street driving.

 

so with it being the same block and all then it would still fit under the stock hood and everything? Also since the car is carbureted then how big would i want to go with the carb to fit a 383. Im interested in power and sound and will this motor give me what i want?

 

383s can put out from 400 to 600 hp maybe more. depends on head/cam and how its built

For the most part it will fit under the stock hood.

that just depends on what intake you use.

 

i believe this was stated already but just to reiterate:
a 383 is the same externally as a 305. (or 350)

A 383 is simply a 350 block with a 400 crank and .030 over

 

It should fit just fine - the big indicator here is intake manifold, carburetor and air cleaner. Any increase in height from the stock height can cause clearance issues. I guess it depends on what carb you were running.

One way to check: measure the 305 from the top horizontal surface of the engine block to the top of the air cleaner. You can then compare that to the 350/383 height. Does that make sense?

I am building my first 383 right now, and so far, the indicators are that I will be getting a fantastic "bang for the buck" engine. You originally said that you'd be buying a complete 383, correct?

 

Actally your right and wrong. Yes externally there the same. I know, im building a 383 right now. What i meant by the intake is if you use a air gap intake manifold (or simialair design) it might not clear the hood.

What your wrong about is a 383 is not just a 350 with a 400 crank and .030 over.

Most engines that are bored are b.c of the wear factor on the cylinder bore.

Also a 383 uses speical pistions with ofset wrist pins.

 

The 383 is the best way to go, especially if you are already swapping engines. The added cost in machine work will be more than worth it once you have it running and nail the skinny pedal on the right. Hood clearance is an issue with any mods that are done to engine intake area. I did not have any clearance issues as I have a Ram Air hood. I have a version of the air gap intake and a drop base air cleaner bottom that the dyno man told me to buy. Carb is another overlooked area. DO NOT go with the cheaped one you can find. Save, beg, borrow or whatever you have to do to get a good carb. Also on the subject of carbs, do not go too large. Bigger CFM is not always better.Beefing up everything behind the engine is smart!! I did mine all backwards. I started at the rear end and then went to the transmission and finally the engine!! Just some food for thought!
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Just a very simple way to explain it without going into specific details!!

 

cool, once I get my LT1 im going to set up a 383 stroker kit.

 

What do you mean "offset wrist pins"?

A 383 uses pistons with whatever pin height is needed for the rod length used. If you're using stock 400 5.565" rods you can use stock 350 pistons.

 

I think 86camaro is trying to be real technical!! Pending on the type of rod and piston combination he is correct on the placement of the wrist pin location on the piston!! All to technical for me!! Bottom line remains the same a 383 if a 350 with a 400 crank!!! There is all kinds of combinations that can be used to get what the person wants!!