Thread: 283 with 327 crank

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Im new to this too so don't worry. the 327 had a longer stroke that will essentially give you more power per stroke. But because the piston travels farther you need a piston with a shorter pin to crown height so the pistons don't come out of the top of the block ( 307's and 327's had the same stroke and essentially the same pin-crown height). The only reason the 283 block is used in this case is because the 283 from the late 50's - early 60's had thick cylinder walls that can be bored out to give you a greater diameter cylinder, again adding to your power. Increasing the 283's cylinders like this (0.060 over) gives you a displacement of about 302 or around there i think

Originally Posted by bjammind13

Im new to this too so don't worry. the 327 had a longer stroke that will essentially give you more power per stroke. But because the piston travels farther you need a piston with a shorter pin to crown height so the pistons don't come out of the top of the block ( 307's and 327's had the same stroke and essentially the same pin-crown height). The only reason the 283 block is used in this case is because the 283 from the late 50's - early 60's had thick cylinder walls that can be bored out to give you a greater diameter cylinder, again adding to your power. Increasing the 283's cylinders like this (0.060 over) gives you a displacement of about 302 or around there i think

A 283 has a 3" stroke and 3.875 bore . If you bore the 283 .125 over and use the 327 crank [3.250 stroke ] you end up with a stock bore 327. Punch the 283 .125 and use the 3" stroke and you have a 302, same as the early Z-28. .060 over makes it a 292.

Here's the skinny on crank journal sizes, compliments of www.mortec.com

Gen.I, "Small Journal"
265...Mains-2.30"-Rods-2.00"
283...Mains-2.30"-Rods-2.00"
302...Mains-2.30"-Rods-2.00"
327...Mains-2.30"-Rods-2.00"

Gen.I, "Medium Journal", includes "Vortec" 305 and 350 thru '98
262...Mains-2.45"-Rods-2.10"
267...Mains-2.45"-Rods-2.10"
302...Mains-2.45"-Rods-2.10"
305...Mains-2.45"-Rods-2.10"
307...Mains-2.45"-Rods-2.10"
327...Mains-2.45"-Rods-2.10"
350...Mains-2.45"-Rods-2.10"

Gen.I, "Large Journal"
400...Mains-2.65"-rods-2.10"

So if you do this
" If you bore the 283 .125 over and use the 327 crank [3.250 stroke ] you end up with a stock bore 327. " Do you end up with the same power as a stock 327 ?
I have an old 283, early 60's sitting in the garage but I was told that it is a 60 over motor, can it still be used and if so what type of dependablity can you expect out from it.

A 327 is a 327 no matter how you look at it. You should be able to get the same power as any other 327 with your bored 283 block. If you decide to have it bored .125, make sure you have the block sonic checked and magnafluxed first. And make sure it is an early block rather than a later one as later ones have thinner cylinder walls and cannot take a .125 bore. A .125 bore on a 283 was pretty common back in the '60's when I was a young'n.

Good talk, but aren't we going to far here? Just joking.. what revs could you do with the 292 combo?

It all depends. If you want good street manners, 6000-6500 rpm is about the limit. Over that, you get into big bucks and street-ability issues.