Thread: 283 To 327

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How far can you bore a 283 ? I have been told a late model 283 (66 or later ) block was the same block as a 327 just not bored as much as a 327 . I have a balanced rotating assembly for a small journal 327 crank . The problem i have is I cant find a small journal 327 block . I hoped to bore a 283 out enough to put my balanced parts in

If you had a '68 283, the 327 crank will fit without clearancing. That's because the block is really a 307 piece, with all the room for the longer stroke crank. Any 307 will do, if you can find one. 283's were often bored to 4", making a 301.

If you had a '68 283, the 327 crank will fit without clearancing.

The ones that will accept the 327 crank readily have dished cylinders and the crank clears the block.

My interest was in how to determine that the 283 was actually a 283/327 blank, therefore safe for boring to 4" without sonic testing. Maybe the dished cylinder is the key.

Bert

If it's a 283/327 block it will have a casting number common to both the 283 and 327 like 3789817 or 3790721

307 BLOCKS HAD LARGE JOURNAL CRANKS. YOUR RIGHT ABOUT THE 66-68 283'S BEING ABLE TO BE BORED TO 4" AND USE THE SMALL JOURNAL CRANK.