283 pistons
 

Does anyone make a stock replacement shelf flat top 283 piston larger than .060 over? This would be for a restoration project and the block is at .060 now. Early 721 nova block.

Re: 283 pistons
 

at one time Federal Mogul made them--- not sure if they are still available--FED 387

Re: 283 pistons
 

Check with Egge Machine. They even have 4in 283 pistons for a old school 301.

Re: 283 pistons
 

Jim,
Looks like Silvolite has them in .080, part number 1412.

Hope this helps,

Re: 283 pistons
 

Thanks for the info.

Re: 283 pistons
 

That block will go to 4 in without any problems, save the hassle with getting the big overbore stuff. Put a 327 SJ crank and stock 4 in bore piston and have fun. Most of 721 blocks were good pieces and were built to go to the 327 in the 65 cars. Tom

Re: 283 pistons
 

Tom, that is what I intended to do with this block. I am selling this block and the guy who needs it for his 64 nova is afraid it will run hot at 4.00. I told him that it has been done before but it scares him. Oh well go figure.
BTW I also have a 3862194 block from a 67 nova, are these as thick as the 721 blocks? Never had it sonic tested.

Re: 283 pistons
 

The 194 is a good block for a 283 street car. It is as thick as any regular 283 block. Probably a better choice for a 283 street car. The 721 block is an awesome 283 race block! It would be a shame to waste it on a street car! Gm made these same blocks into 327s for Chevy 2s so overheating would not be due to thin walls.

Re: 283 pistons
 

Is it worth the cost or necessary to put 4 bolt caps or fill the 721 block for a race car motor? This block I have was from a old modified motor. 3.935x3.00 292 cubes. Not filled and stock caps.

Re: 283 pistons
 

I guess it depends upon the power and rpm. We put studs on ours, but kept the two bolt caps. Never had issues and went 8000 plus in our stocker.

Re: 283 pistons
 

I ran a 721 block for years with arp bolts and stock caps ,broke it so many times that the caps no longer had that pinch on them but it was fast. Turned it 9200 all day long. One thing you would what to look for is where the cam tunnel is at, I have seen pretty bad ones over the years. That core shift would somewhat tell how thick the clys would be but are a over 100ths + thicker than a stock 283 block . The 721s also were suppose to have a better main webbing in the block itself and a higher nickel content, that info I got from a old chevy performance book. I have a fresh 721 waiting for when I get my car done 4 bolt caps filled 50 mm roller cam bearings and still 30 lbs lighter than a bowtie block. I am always looking for them and they are really hard to find now days Tom