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Hot Rods 307 chevrolet chevy crate motor.

Discussion in 'The Hokey Ass Message Board' started by 325w, Dec 19, 2016.

  1. A friend told of his friend that had a 307 Chevrolet crate motor. I called the guy and the story is he saw an ad in a rod mag for the 307 from Chevrolet. He ordered one. That was over twenty five years ago. He had an old truck but sold before the install. He has a rebuilt PG also. Built at least twenty years ago. He would love to sell both. I have to make a resonable offer. What is a reasonable offer. I'm thinking that the motor needs reseal and valve seals. PG Needs seals also I would think.
  2. Sitting that long it may need valve springs as well as some would have been open all this time in one position.
    LOU WELLS likes this.
  3. upspirate
    Joined: Apr 15, 2012
    Posts: 2,299


    Didn't 307's have bad cams that would wear out fast?
    JeffB2 and belair like this.
  4. henryj1951
    Joined: Sep 23, 2012
    Posts: 2,306

    from USA

    my henry j sat, un turned, not started for 26 years.
    runs like a top 35miles per gallon 3 speed overdrive.

    and THEN or so a its been running for the past 5 years without
    changing a thing
    stillrunners and kidcampbell71 like this.

  5. hotrod1948
    Joined: Jan 17, 2011
    Posts: 512

    from Milton, WI

    307's with cast cams made during the mid to late 70's were plagued with soft cams.
  6. As you said, might be wise to put some new seals in both the trans and engine. Assuming it is stock cam, I doubt there is any bad spring set problem. Could have valves stuck so be careful. Depending on actual date of mfg, the soft cam is potentially a non-issue. How were these stored? A quick boroscope inside the cylinders through spark plug hole could help a lot. Does it turn over even? All sealed up with intake and carb or at least intake taped over the opening? What about distributor hole and thermostat opening?

    As for price, I will say $300 for package deal is a reasonable offer since there is unknown factors. I would break it down $200 for engine and $100 for trans. You could get lucky and it works fine with minimal gasket and seal replacement. The PG is used by drag racing guys, not much street demand for them since so many get the T350 replacement. 307 is decent for street cruiser engine, basically a 283 bore with 327 stroke. But a large journal engine.
  7. 55chevr
    Joined: Jul 12, 2008
    Posts: 985


    307 SBC is not a performance engine. Really an iron dog.
  8. Your price needs to reflect how much you trust the story. I wouldn't pay much for a 307 that I wasn't sure about the history or story.
  9. From the factory, Yes. But there is a long 307 thread on here about making them work and run good.
    1934coupe likes this.
  10. ididntdoit1960
    Joined: Dec 13, 2011
    Posts: 1,030

    from Western MA

    how about we call it a stroked 283......or a bored and stroked 265......does that sound like more of a hot rod motor?LOL - 307s just never came as "factory" performance motors so the perception is they are worthless (much like mopar 400s which were overbored 383s) Ironically the replacement for the 307 (the 305) was marketed as an HO engine for several years and that has an even smaller bore and longer (3.48) stroke....
    Montana1 likes this.
  11. Petejoe
    Joined: Nov 27, 2002
    Posts: 12,285

    from Zoar, Ohio

    Low horsepower dogs in the day.
    Came around the same time as pollution control.
    Wouldn't even take a new crate if it was free.
  12. Atwater Mike
    Joined: May 31, 2002
    Posts: 11,624

    Atwater Mike

    307s are akin to 1300 VWs. (40 HP 77mm bore, 53HP 69mm stroke) Case had large bore for 1500-1600 jugs.
    302GMC likes this.
    1. Hahahaha!!!
    Smokey and duntov built the first 307 in 1955. The glorious infamous reverend 30-30 cam was originally designed for the 307 they built. They zinged a 54 corvette up to 163 mph with it, theirs was a small journal 283 block with a 3.25" stroker crank.

    If you can't copy that build there was something really REALLY wrong with your indoctrination.

    Chevy was not interested in power numbers from their version. They needed an EPA emissions quota average. The 307 is a very efficient design. But if you stick 76cc heads on it the engine is incapable of making NOx emissions gas. Do you know what else you can't make with an engine that can't make NOx?

    You can't build a 307 like a treefidy
    Last edited: Dec 20, 2016
  13. belair
    Joined: Jul 10, 2006
    Posts: 9,015


    Fat hack did thread on them. NOT the dog you thought they were. The lousy cam and emissions doomed them, not their lack of potential.
  14. Shhhhh!
    Every time a thread pops up about 307s the market price goes up. They used to be damn near free.

    I'm going to delete my post in a little while.
    Dan Hay and belair like this.
  15. Speed Gems
    Joined: Jul 17, 2012
    Posts: 6,433

    Speed Gems

    The stock 307 Chevy valvetrain is basically junk anyway with it's soft cam lobes and smallish 1.72 valves. you'll want too replace the cam and lifters anyway and you'll want too get the valve springs that go with it. Button it back up and it should run like a top for you.
  16. Really? Free? C'mon!:D
    Bruce Fischer likes this.
  17. jimmy six
    Joined: Mar 21, 2006
    Posts: 14,920

    jimmy six

    Always crazy to me. Take a 283 and 327 and combine them one way and you have the best SBC (302) ever built. Put them together the other way (307) and you have the biggest POS Chevrolet ever assembled. Go Figure.
    49ratfink, Montana1 and Speed Gems like this.
  18. Mr48chev
    Joined: Dec 28, 2007
    Posts: 33,980


    From personal experience a 307 with a "Z28" hydraulic cam out of a mid 80's engine with power pack heads and a four barrel will run pretty strong. Had that in a 70 Chev Pickup that my son did a lot of street racing in in the late 80's.
    frozen_bohemian likes this.
  19. squirrel
    Joined: Sep 23, 2004
    Posts: 56,082


    pictures? no pictures? I bought a crate 454 from Chevy over 25 years ago. That was long after they quit putting 307s in cars. I wonder when the engine was built? and where it was built? I wonder if it's a Chevy and not an Olds? :)

    But yeah, we need pictures to see what exactly it is that you're talking about. Something doesn't add up.
    belair likes this.
  20. Give me a 307 any day, just a 283 with a PCV system. I've stated before we used them in stock car claimer classes and twisted them up to 7k all the time. I had a Chet Herbert cam, stock intake and Holley, recurved distributor, better valve springs that moved from engine to engine.
    Bruce Fischer and loudbang like this.
  21. dorf
    Joined: Dec 5, 2008
    Posts: 1,087

    from ohio

    i worked with a guy who bought a new pu with this engine i believe it was 68 he said the fastest it would go was 75 mph
    Bruce Fischer and Montana1 like this.
  22. 56sedandelivery
    Joined: Nov 21, 2006
    Posts: 6,695

    Member Emeritus

    IF the engine is "good", meaning it's still in the crate, it's not full of dust, mice/rats nests, or rusty, I'd think $250 for the long block, with paperwork; I would replace the cam with something more performance related, and swap to some better heads to up the CR, and have larger ports/valves. The Powerglide, only if it's an ALUMINUM Glide, is a $75-$100 trans max as a rebuildable core; I usually get my core Powerglides for free to $50 max. IF it's rebuilt and he can prove it with paperwork, and is still in good shape (same as the engine), has a converter, then it "might" be worth $150 to someone wanting a Powerglide for mild build. IF it's a cast iron Powerglide, then it's only worth it's weight in scrap as far as I'm concerned. IF you have a car/truck that CAME with a cast iron Glide, and it's complete, $100 max. I see guys all the time thinking the grungy, rusty, aluminum Powerglide they've had sitting behind the garage for years is worth $400, "because that's what all the drag racers use". I don't even look for a Powerglide unless I have someone asking for me to build them one (I don't do this professionally; I'm a Retired X-Ray/CAT Tech). I do have a couple of built Powerglides in my stash of parts, and a ton of aftermarket parts for them. So, for engine and trans, I'm in the $350-$400 range,. I am Butch/56sedandelivery.
    31Vicky with a hemi likes this.
  23. big duece
    Joined: Jul 28, 2008
    Posts: 6,830

    big duece
    from kansas

    I would pull the heads first and see if any moisture has rusted a cylinder wall. THere is always one or more valve open. Where the exhaust ports covered that entire time?
  24. And there's nothing anyone could have done to make that better. EVER!!!
    Kindergarden level hot rroding is a cam swap. Third grade level is a new set of heads. Your coworker never made it to kindergarten.
    Failed the indoctrination
    Last edited: Dec 20, 2016
    ClayMart and shawnsauto1 like this.
  25. My Dad bought a brand new '71 GMC 3/4 Ton PU with a 307 (2bbl.) that wouldn't pull the hat off a tall cowboy, until we turned the air cleaner lid over! Then it would go 95 mph!

    Don't ask me how I know! :eek:

    It did start to burn a lot of oil after about 100,000 miles and we found out it had a soft block. Both rear cyls. wore slap out...
    loudbang likes this.
  26. Then on the other hand, a high school buddy put a 307 in his '67 Cam... with double hump heads and a Crower cam ( I don't know the #'s) and 750 Holley double pumper and wound it to 6500 rpm, and out ran my other buddies 375 hp 396. Both were 4 speed cars.

    Made me a believer in small bore sbc's!
    31Vicky with a hemi likes this.
  27. Alaska Jim
    Joined: Dec 1, 2012
    Posts: 319

    Alaska Jim

    the chevy 305 is the eng. with all the cam problems not the 307. the 307 , while not a performance motor is very durable and a good eng. the can be made to run pretty good with a set of 350 heads and a 327-350horse cam. and a good 4bbl intake and carb
  28. 307 was first and had cam problems.
    Plenty of 307s were dead of flat cams long before the 305 hit the scene.
    Nylon timing gears from the factory didn't help either
    Bruce Fischer likes this.
  29. I had a 307 in a '69 No.. with a flat cam on #2 cyl, but I didn't know anything about that stuff back then. Had I had some experience and money, things would have been different!

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