307 block

Is the 307 block the same as the 350? The 72 i just bought has a 307 and I was wondering if it will handle a 4.030" bore and a 400 crank to make the famous "383".

I am 99% Sure they are not he same:(

It figures. I knew the 305 wasn't but i didn't know about the 307. Thanks.

Here's some specs: http://www.nastyz28.com/sbchevy/sblock.html

307 is just a 283 with a 327 crank, right?

307 is just a 283 with a 327 crank, right?

That's what I've always heard. The 307 also has very poor heads for power. It was an "economy" engine.

The 307, as Jim Richardson says in his small block book, was an attempt by GM to make a "Joe Stationwagon" engine to go along with their 327. It has a 3.875" bore and a 3.25" stroke (same stroke as a 327). he says you can "usually" bore them .060 with no trouble.

My opinion is that they are overlooked for street drivers. They still have the V8 sound we all want and will give you a lot of fun for very little ****. However, if you are thinking of doing any machine work on them you should take a look at all the really cheap 350s in the junk yards. I have seen Gen 2 350s, roller cams and all, going for $100 or so.

Dave

307 is just a 283 with a 327 crank, right?

The crank is a large journal crank, not small journal like most 327's. It is the same stroke though.

327's came in both small journal and latter, large journal versons. Years ago I built 2 327's buy using 307 cranks in 350 blocks. It was a cheap solution at the time.
Ron

so could you use the 307 block and bore it to come up with a 327? I was thinking of rebuilding the 307 with a 30 over bore and a set of good heads !

I've found there is very little you can do to make a 307 run well. It kind of boils down to how fast do you want to go, and what do you have to spend. I'd suggest a 350 before you throw money into a 307. I will say though that I had a 71 RS camaro with a 307 with the L79 cam, Edelbrock performer intake, and 600 cfm holley that actually ran pretty decent(not fast) decent. The cam made it sound way better than it was.

Thanks for all of your replies. I will look for a used 350 but in what vehicles were 4 bolts put in?

what vehicles were 4 bolts put in?

If you're building a mild street engine, you don't need a 4 bolt block. I've run plenty of 2 bolts in 11 sec. cars.

You can make a 307 run well with the right combination of parts. Remember that it's a smaller engine. Bore it .060 and build it like you would a 327, or if you have good rods and pistons, build it like a 302. It will run just as well as either of these engines in a street application, and a little better than the 302. Sometimes you need to work with what you've got, and I don't know about So Cal, but around here, finding cheap 350's dosen't happen. Finding one in a junkyard? Not likely. When you do find one in a junkyard it's between $350-500 for a builder, that's why I built my 307 for my Camaro and it runs just as good as any 327 I've had. It's all in the combination of parts. Just remember that when you're figuring out your compression ratio, stock replacement 307 pistons are around .030-.035 down in the hole on all the ones I've ever rebuilt.

If you're not concerned about date codes and the like, think trucks. Especially 3/4 ton, or van. You might even find a small block 400. Now that's the ticket.

$300-$500!!:eek: Dood!! Ever once in a while Pick-N-Pull will put them on sale to clear their inventory and you can get Gen 2s for $100!! You figure that EFI engines will live at least twice as long as the old carborated engines with regular oil changes, and there is a lot available. I particularly like the light truck 5.7 from the early to mid 1990s. Those are stout!

What kills us is machine work. In the East Bay where I live most shops are billing at pretty close to $100 per hour. I had a block cleaned, line-bored, decked and honed with pistons fitted (it was already +.030) and it cost me a bit over $700

Dave