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Odd 307 build help needed

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77crewcab

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Hi guys I need some help in planning an engine build. This will be for my 63 nova. I am just looking for a good cruiser with decent economy hopefully 20+ mpg on the highway. I will be using either a 700R4 or a T5 tranny and probably about a 3.42 gears.

Now for the engine, it will be a stroked 283 bored .060 over to give a c.i. of about 317. Yes I know this will basically be a .060 over 307. This will be running a TPI intake and probably this cam from Summit, http://store.summitracing.com/partdetail.asp?part=SUM-G5000&autoview=sku. I need some help picking out some heads to use.

The contenders are:
265 vette power pack heads
305 casting #416 heads
Vortecs (I know I will need a special TPI intake base)
S/R Torquer 305

This is a project using mostly parts I already have laying around. I already have the power pack heads and the 305 heads. Just not sure which would be the best for what I am needing. My gut instinct is the Vortecs, but I would like to hear what ya'll think. And before it is said yes I could get more power with a 350, but I really don't need more than 250-300hp which can be obtained easily wit this combo. So what do ya'll think would be the best heads to use?
 
You might as well get a different engine for the cost of going vortecs on TPI. Seriously.
 
The very first thing you need to know is that the stock bore of a 283 is 3.875 and IIRC you can't use heads with the 1.94" diameter intake valve or the valve will hit the cylinder wall. Even being bore .060" will only make the bore 3.935" which still isn't large enough to clear the 1.94" valve.

On the 265 heads if you look closely you'll find that the valve cover bolt holes are not symetrical like other chevy's so you'll need the valve covers to match the heads.

Do you plan on using a rear sump oil pan or the original front sump pan? If you use the original front sump pan then the oil pump, oil pump shaft and also the oil pick-up screen are specific for chevy II ONLY. Also unless the car has already been converted to a V/8 the frame stands are different than the 4 or 6 cylinder engine and will need to be changed as well. If you need any of those items then J&W Nova parts in West Virginia is a good place to go.
 
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The car is being converted to aalow a v8 with rear sump (front clip and MII susp). I know the Vortecs will work, Super Chevy did a 307 build using the Edelbrock E-tec heads with the same valve size on a stock bore 307. I just wonder if the cost of Idoing the Vortecs would be worth it since I am not looking for massive power. The SC build made 315hp and over 300tq which sounds good but I could live with a little less power if it means using the heads I already have and saving some money in the process. I have the valve covers for the power pack heads with the staggered bolt pattern. I am leaning towards using either those or the 305 heads but both will need a rebuild reguardless. As I under stand it both the power pack heads and the 305 heads are close to 60 cc. Which would ya'll recomend. Yes I know I could go crazy and have a big block in the nova, I just don't need that much power for this project. Just want a good cruiser that will be reliable, and decent on fuel economy. I do have a 496 sitting in the garage, but that is slated for another project.
 
Go with the 305 heads. They already have hardened seats, unlike the 265 heads. That will save you some coin right there.
 
Why not just go with a vortec 4.3l? The car is the perfect match for the engine. It won't have to try to move it (which is why the 4.3l gets bad mileage in trucks), it has great throttle response, and it won't have the robust hp waiting for an itchy foot.
 
Cause I have too much crap laying around I need to use and this is the perfect candidate to do so. Good point on the hardened seats in the 305 heads I had forgotten about that. I guess that makes my decision right there. Thanks guys. And yes I know i am totally crazy for building a dreaded "307" but, I have always been crazy, it has kept me from going insane!
 
77crewcab said:
Cause I have too much crap laying around I need to use and this is the perfect candidate to do so. Good point on the hardened seats in the 305 heads I had forgotten about that. I guess that makes my decision right there. Thanks guys. And yes I know i am totally crazy for building a dreaded "307" but, I have always been crazy, it has kept me from going insane!
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I actually want a 307 for a project I have in mind... :wink1:
 
I'm a little confused about the title of this thread "Odd 307 build help needed".

You are asking about boring a 283 block .060" which still would only make the engine a 292 ci. :confused: Is there something i'm missing?
 
4X4HIGH said:
I'm a little confused about the title of this thread "Odd 307 build help needed".

You are asking about boring a 283 block .060" which still would only make the engine a 292 ci. :confused: Is there something i'm missing?
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He said he was stroking it. That will give him the xtra cubes.
IIRC all chevy did to make the 307 was use a standard bore 283 block, a 327 stroke crank, wimpy cam, and some real crappy heads. The 307 was basicly designed for economy and fuel MPG.

77Crwecab. You are not building a dreaded 307. You are building a bored and stroked 283. I think it will run great with TPI.
IMO the 305 heads will be your best bet.416 are good 305 heads. Beings it is a small journal block I would use a steel crank and forged rods if you are planning to make some power or racing it.
 
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I totaly skipped right over the stroked 283 block. :doah: At any rate, he will need to use a small journal 327 crank since he must also use the small journal rods. Also a 283 block at .060" oversize should be sonic checked for wall thickness as they are very thin even at .040" oversize.
 
X2 on the sonic check. Have that done before you buy any.060 over parts. .060 is pushing the limit for a dependable street machine. There could have been core shift when the block was cast. There could be thin spots that cause overheat problems on the street. So its best to have it checked out. IIRC older 283 have thicker walls than the newer ones. LOL if you can call a 45 year old engine new.
I rember back in the day people used tp punch 283s out .125 to make a 301. But they could not run on the street.
 
Thunder said:
X2 on the sonic check. Have that done before you buy any.060 over parts. .060 is pushing the limit for a dependable street machine. There could have been core shift when the block was cast. There could be thin spots that cause overheat problems on the street. So its best to have it checked out. IIRC older 283 have thicker walls than the newer ones. LOL if you can call a 45 year old engine new.
I rember back in the day people used tp punch 283s out .125 to make a 301. But they could not run on the street.
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Weren't the 283 and 307 the same except for the stroke? I thought they both used the 3.875" bore.
 
Yes that is true but the castings were different. The 283 casting I have was also used on 327s so I have plenty of meat to the walls. I have already had this block checked and bored .060 over. The machine shop said if it wasn't a shared casting with the 327 they wouldn't even do it. However being that it was the same casting there was no problem.
 
I am getting ready to do a 307 lrg jrnl soon. I am hoping to use the 305 sr torquers. 58cc and 1.94 valves. It should be a nice little cruiser. Good luck and enjoy.
-Lance
 
77crewcab said:
Yes that is true but the castings were different. The 283 casting I have was also used on 327s so I have plenty of meat to the walls. I have already had this block checked and bored .060 over. The machine shop said if it wasn't a shared casting with the 327 they wouldn't even do it. However being that it was the same casting there was no problem.
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Where do you come up with this "same casting" info. The casting number will only come up as either a 283 or a 327 but not both since the blocks are different. :confused:
 
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