The six in my El Camino died and my buddy gave me a good running 307 SBC and turbo 350............I know what most people think about this motor, but it was free and I do need a motor.........I remember Fat Hacks great post about reworking a 305 SBC, any good info on the lowly 307? Thanks guys.......
despite the awful rep these things have, i thought there was a pretty stout one in the 1st PHR engine build-off. maybe someone can get to a copy, unfortunately, i don't have access to mine.
It's basically a 283 with a 327 crank.With the small displacement you'll get good gas milage and more tourque than the 283.I'm putting my 307,with H.O. 305 heads in my rod.It should work good.
take the 307 punch it out to a 4'' bore and add a 305 crank and you get a standard bore 350. The difference in rebuild parts between the 307 and 350 will probably make up the difference in cost plus you have more engine in the end.
Just be aware of the lack of nickel content in the 307 the block is very soft. On a typical rebuild when you hit 40,000+ miles, bore wear will be a issue. Just my .000002 worth.
The thing that hurt the 307's reputation the most was that most of them came from the factory with soft (unhardened) camshafts that wore out quickly, leaving the engines WAY down on power. But, they ARE small block Chevys, so the world is your oyster when it comes to replacing the garbage stock camshaft! Boring one out to 4" is pushing it...you CAN do it successfully if the block in question sonic checks okay, but I wouldn't advise it. A clean-up overbore of .010" to .020" is about as far as I'd go...if it needs more than that, seek a new block. (Of course, you may not even need to bore it...check the cylinders for taper and cut the ridge out with a reamer...if the taper is within spec, a good hone with deck plates is all you'll have to spring for, along with new rings.) Beyond a basic rebuild, you'll find anything and everything you could possibly want in the way of bolt-on performance parts...intake manifolds, camshafts, distributors, fuel pumps, dress-up items and accessories are all common to other small block Chevys, so coaxing more power out of a 307 is no different than tweaking any other 305, 350 or 327...stick to a maximum cfm rating of about 650 on your carb, run a good distributor with a crisp advance curve, a decent dual plane intake, mild performance hydraulic cam and a set of headers on the thing and you'll be happy with it. As for the trans, a TH350 is the go-to tranny of choice behind street small blocks...a shift kit and maybe a slightly looser converter is all you'll need there!
Thanks for the great info folks..............I just got back from the garage and after checking the casting #'s it seems the free 307 turns out to be a free 305.........looks like I'll return to the Hacksters small block post in the Tech O'Matic.........Hope all this info helps someone. Thanks again CT.
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