Who's running a 307 Chevrolet i have a friend that has one fresh built with a tranny 30 over motor came out of a early 70 's truck are they any good.Would you run one.
They suck in stock GM form. Better cam and smaller cc combustion chamber heads really wakes them up. I'm quite tickled with mine
the biggest problem with them in stock form is the heads. a set of good flowing, 305 heads, a mild cam (very mild, its a small motor), and they are pretty good motors.
Yeah, I think the 307 is how they used up all the old 283 blocks and 327 cranks. I would use it, you bet!
Smokey and zora built the first 307 back in 55 or 56. Zora also designed a special cam for it , the Duntov 3030. They went over 155 mph with it back then.
Got one in my '38 Ford pickup, came out of a '68 GMC pickup with low miles but rusted to pieces. Later 305 heads. The ones in pickups had a better cam. Edelbrock intake and 600 Holley, otherwise stock. As much power as I really need.
From the late '60's to well into 1970;s. OMC put a Q-Jet 4bb carb and intake on them, along with a slightly hotter cam and sold them as marine engines, rated at 225 and 235 hp. Mart3406 =======================
In stock form the 307 in 67-68 pick ups had a soft cam. Lobes went flat and the fuel pump lobe flattened. On many. I'm sure most that have survived have been up dated by know.
One of the "overlooked" as everyone was going for 327s and 350s ,hey it is a torquey truck motor with a 327 stroke and 283 bore , with decent heads ,cam and intake it could be a decent street engine.
------------------ The 'soft cam' problem wasn't unique to the 307 - the problem was fairly common to all SBC's in those years, even the 327's and 350's. As you stated too, any engine that is still running now that had one of the soft cams, has had it replaced long ago - most likely when was still young and still on warranty even. It's also not an issue, because for any sort of 'performance' build, even a mild one, you'll want to replace the stock cam with something better. Mart3406 ============
not to long ago (about 9 years) my father in law went looking for a 30 30 cam. had one hell of a time finding someone that new what he was talking about.
G'day, They didn't actually use up any old 327 or 283 parts. The 307 got the 2.1 rod journals and the mid size 2.45 mains. No relation to the old crank or blocks. They do make darn good motors though. Ran one for quite a while in ot drag car with a baby blower (weiand) and it was always a handful. High 11's out of 5 liter isn't bad. ms
Check the cam- as was said before, they are soft and prone to rounding. Other than that, it's a good engine. Had one in my o/t '70 Nova with a Rochester 2 barrel and powerglide. It was quiet and quick
It wasn't all the cam's fault. GM did away with the squirt grooves in the rods, and less oil got sprayed up to the cam, causing premature failures.
The Jalopy Journal
