Thread: 283 with 327 crank

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Hi. Im going to purchase a torn down 283 sbc ('58-'61) thats been 0.060 overbored. It comes with a 327 crank and connecting rods, and also with 307 pistons (0.060 oversize). it also comes with the original 283 crank which i believe has been machined but im not sure what has been done to it.

My question is, can I use the 327 crank and rods with the 307 pistons? or even the 283 crank? I guess if i use the 283 crank i'll have to get new rods. I want the bigger stroke but I don't know if the 327 crank will fit the block, and if it does, and I use the 307 pistons, will there be an issue with the total height of the pistons?

Also, the heads are 283 powerpack heads, 64cc from what I could tell.

It seems like kind of a mess but Im getting it for pretty cheap so I'm not complaining. Any help is appreciated. Thanks,

A 283 and 307 both have the same bore. A 327 crank has the same stroke as a 307(so the piston deck height is fine). The problem is... the 327 crank. A 283 only came with a small main journal crank(2.30"), but 327's came with both a small main and large main(2.45") journal crank. If the journals measure 2.30" or near that(turned down) you will be fine. Still I would assemble the short block "dry" to make sure you have what is said to be. Hope this helps.

Before we go any further-we need to know the main bearing size of the 327.

I believe it's a small journal crank. its in the block right now. The guy I bought it from seemed to know what he was doing, but I'm not assuming anything haha. I haven't had a chance to check numbers or measure anything on the crank because the block is off the stand and the crank is inaccessible right now. but I'll make sure when I take a look at everything on the weekend. does the fact that it fits in the block mean it will work?

The piston pin heights are different as well i believe
Mark

Whats the number on the block, on the bellhousing behind the driverside cyinderhead? I think all connecting rod lengths were the same(5.7"), except for the 400(5.65)? Anybody know for sure?

The piston deck height should be okay. as far as I know chevy didn't really change the overall cylinder block height, they just changed the piston-to-crown length to accommodate longer stokes. so the 307 pistons with the small journal 327 crank and 327 connecting rods should be fine - because all connecting rods share the 5.7" length except the 400's. but i did notice that the 307 cranks had a larger rod-journal diameter, so 307 connecting rods would have to be used in that case (just in case anyone is wondering).

oh the block number is 3756519.

thanks guys

.I am new to this sight and new to this building rods. What are the benefits of mix matching parts , the crank and rod from the 307/327 to the 283 block ? Hopefully this isn't a dumb question

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.