I have a 307 Im putting in my 69 chevelle. I was wanting to know what all can you do to get more horsepower out of it.[/quo

throw it away & get yourself a big block...........ANY big block

 

New dual plain intake and 4-barrel carb.
Exhaust headers.
HEI ignition.

NITROUS.

Seriously, I wouldn't even put money into the short-block. No new camshaft will be of much gain. Only add bolt ons that could later be swapped over to a better performing 350 or 383 small block.

 

seriously, the 307 is not worth the cash to make run...I know,I know a bunch of guys are gonna say "I had one & it ran great!" IMHO no they didn't. (flame suit on!) Like said earlier. either put it in as is since its free & save your money for a 350,383,400 or a big block

 

Jack it up and put a big block under it. That is the easiest way to make in run faster. Jb

 

Like dreis454 said, it's not worth puting any money into. Too many negatives; small displacement, small ports and valves; are just the start of whats wrong with them. It will be a step up from your 6 banger though, just not a good platform for performance.

 

thanks for the info

 

with a mild cam, headers, performer or performer rpm intake, and a 600 holley you can run 16's or 15's in the quarter (w/th350 or 400, with apg probably 17's or 18's) anything quicker than that and it will not be cost effective. it will be miles above the 6 banger either way

 

I hope not, that's what mine ran basically stock with just a K&N in the OE housing and an HEI with a Jacobs ignition box. Both were essentially "free" as I had them lying around from another vehicle I had sold.

Carb = $300-400
Headers = $100-300
Intake = $100-200
Cam & necessaries = $400-500
Machine work and parts, to rebuild a short block = $1000-1200
etc.

350 core = $50
(any of the others will then produce MORE results)

Hmmmmmm......

So, what's the cheapest upgrade to a 307, that gives the most results, again? I'm having trouble figuring this one out....

Sometimes, the most EXPENSIVE engine, is the "FREE" one.

I wouldn't put all that money into a 307 but you're right. I got a "free" 350 one time only to find out it had a 307 crank in it and 2 sleeves repairing a major explosion. This was AFTER it was already at the machine shop. By then it turned in to one of those "Well, you may as well...." situations and "project creep" set in. I spent a ton of money on a fairly mild engine but it was my first one, so lesson learned.

 

agree about an intake, carb, HEI ignition and good exhaust so you can change it over to a better engine later

it will help a little and sound nice anyway...

 

They have a small 2 barrel,so if you went with a Performer & small 4V or Q'Jet,it would make a big difference. Dual exhaust is always good for some power.

 

Carb = $300-400
Headers = $100-300
Intake = $100-200
Cam & necessaries = $400-500
Machine work and parts, to rebuild a short block = $1000-1200
etc.

350 core = $50
(any of the others will then produce MORE results)

Hmmmmmm......

So, what's the cheapest upgrade to a 307, that gives the most results, again? I'm having trouble figuring this one out....

Sometimes, the most EXPENSIVE engine, is the "FREE" one.

 

Sometimes, the most EXPENSIVE engine, is the "FREE" one.

The above is so true.

before going through thr aggravation of putting in a 307. If you cant afford to move up to a displacement of 350 or more...keep the 6 cylinder...save your pennies.

With that being said I have had so much fun many times with that strait 6 in jeeps....putting on 6 into 2 headers, a new cam, and picking up used offenhouser 4 bbl intakes and putting on a small 4 bbl carb. They are not fast but you can beat the hell out of those 6's all day long and they always run. Reliability factor rating A+!

 

I'm beefing up my 307 by pulling it out and replacing it with a 496. Thats the only solution I could come up with.

 

i would put a set of pre 87 HO 305 heads on it, with a little cam ( such as the summit one... 442/465, 204/214 duration) a performer intake, 600 carb, HEI, headers, and dual exhaust. i garantee you will have close to 300hp, if not more.
should be a real stout runner, and suprise alot of people.
307's are good engine, they just need a good exhaust, intake, and possibly little better heads, and they can run with most 350's.
its just a stroked 283.

aaron

 

Flippin' Rat Pack they are, aint they!?!?

Hey, I'd run the six myself, since a 307 won't ( unless, read on ) really turn your crank much.

Now, I;ve never done this, BUT, I;d do the same thing I'll do to my 95 Tahoe. Instead of rebuilding heads, I'm going to Vortec the top end. I know the bottoem end is sound. At the same time, I'm putting a new cam in. REally, if I;m "flush" at the time., I'd like to do a hydraulic roller, but a hydraulic will do. Run in should be no issue with EFI. Not much duration for a 307 though. 220@.050 is alot.

Check the bottom end to ensure its sound. ( pull at least #1 rod and main caps. but I'd do them all - hate to freshen it up and find a knock on startup.) If the oil filter is still on, you;re in luck. Cut it open and see if there is metal in it.

Instead of rebuilding the heads, go and buy a done set of Vortecs that will allow .500 lift. Stick an ultra short duration ( 210-215) , .480-.500 lift 110-108 lsa cam in there, heads and carb, as Mike says, and you'll be layin' rubber at will for sure. it'll run ya about $700 if you shop carefully, + headers, + HEI.

Build a 383 bottom end up and bolt all that stuff right on it for some real fun down the road! Vortec 383 with a good cam ( there'd I'd go roller) will give plenty of rats the run around.

Or find a stock 454 and some 215 heads and do a el cheapo 400+ lbs ft beast. I like the rat! 427's are kinda fun since at WOT they'll break the tires loose at around 6000, just as they hit their stride. 7400 rev chip MANDATORY! :thumbsup:

Do the top end on the 307 ( if its mint down below) and plan on your 383 short block later. IMHO anyway!

 

Look, build it just about like I always mouth about doing to the little 327 and go!!

And a set of medium valve double-hump heads will work just fine on it!!

Sure, it WON'T be the fastest of the smaller SB's out there, BUT, imho, it is still a darn good SB!! To me, much better than the 305!!

BUT not quite as good as the 283 b/c of it's short stroke, OR the 327 b/c of it's 4" bore!!

pdq67

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for a street motor the 307 is going to make a little more usable power than a 283, but not as much as a 327. it is basically just a stroked 283. if you know it's a good motor it won't hurt to run it, and do what others suggested, buy an intake and carb and headers and exhaust that you can use later on a 350+ engine. i'd invest in some 3.73 gears too, if possible. i wouldn't put much money into the 307 itself though, only things that you can re-use on a bigger engine. i think you can get better power out of the 307 than you can a 305. just to make sure though, this 307 is an old motor, right? not an Olds motor?

 

For the amount of money required to rebuild and enhance it's (307) characteristics a bit, you'll be money in the bank ahead buying a crate motor and slapping a cam into it. Plus by the way good luck finding a set of frame mounts for it.

 

....Plus by the way good luck finding a set of frame mounts for it.

SBC frame mounts arent hard to find....

 

If you want a good gas mileage motor keep the 307, buy some Edelbrock E-TEC heads and a mild camshaft. It would be good for at least 300 hp.

 

My 68 came with a 307/powerglide/3.08 gears
-the following boltons were there when I got the car(otherwise stock) 1-1/2inch headers and 2-1/4inch duals+performer intake with 750vacumn secondary = 15.60s
added turbo350/11inch converter (both were lying around) = 14.90s(2.08 60')
It wasn't such a bad deal, with the stock cam and limited gear it was a decent cruiser that was easy on gas and not at all tempermental.

 

And there ya have it. Edel E Tec are Vortech style?

 

Interesting thread. My '65 has a swapped-in 307 from a later Chevelle. PO evidently overbored the motor (supposedly to 327) and put in a hotter cam. It was a Weiand intake and a Carter AFB carb. I put an HEI with MSD box and headers with 2.25 duals. I wouldn't personally spend much money on a 307 other than -- as others have stated -- for parts that you can swap to the next SBC.

With that said, the motor does run very well. Runs clean and strong. Starts every time. Runs cool. For a street car, there's a lot to be said for that. It would do a lot better with deeper gears and a proper torque convertor. Actually, seat of the pants feels like it would do pretty well with a 4-speed.

Thoughts? Could I put on aftermarket heads that would make the motor run even stronger yet be swappable to the next SBC?
d

 

If money is the issue ( assume it is), I would jus drop the 307 in, 2 barrel and all. Get some cheap 1.5" headers that you can reuse later and put a 2-1/2" exhaust behind it all - so it is done and in place. Spend any available money on two important items first. Get some gears in the rear (3.73's are a good start) and get at min a 2400 stall converter.

 

I would jus drop the 307 in

I agree. Make a decision up front: either use it like it is, or throw it away.

The problem is, the 307 ITSELF, isn't where the money is, once you start spending money on it. The money all ends up in OTHER STUFF. The 307 doesn't save you anything at all even if it's "free". And, most importantly, the SAME MONEY will do more for you if you spend it on something else.... meaning, you spend an equal amount of money on a 307 or a bigger engine, and you get less. Think about that: spend the same, get less. Definitely not the program most people would embark on deliberately. The cost of upgrading to a bigger engine is NEGLIGIBLE compared to even some of THE MOST MINOR mods, if you're already having to dig into the short block.

So, if it's running and useable, go ahead and use it, especially if all you're looking for is something to push the car around. There's not a thing wrong with the 307 as such, it's a perfectly OK motor, and people would probably love it if we were in a motor vacuum and that's all there was. But if it needs work, PARTICULARLY the short block, it isn't worth it. The $50 for a 350 core is BY FAR the cheapest horsepower money can buy. It's the same argument against rebuilding a 305: THE MONEY IS NOT IN THE CORE. The money is in what you do to the core. So there's no sense in spending money on a core that's less than ideal.

Romantic stories about what OTHER people did to their car in high school, or back before 350s were as cheap and plentiful as they are, or stuff like that, won't make YOUR CAR or YOUR ENGINE any better. Don't let that sort of thing influence your decision.

The 307 block is the same, externally, as any other SBC; the thing about the motor mounts that's different is the CAR SIDE of the system. The parts that 307 CARS came equipped with are the difference, not the 307. It's not really an issue until you get involved with headers and such things.

 

I really have to disagree with the posts that say not to ue a 307. Granted, in it's stock form, you're not that far ahead of the 6 banger. But like all small block Chevies, a set of small chamber 202's like World Products, hi-rise intake and Holley carb, headers, a good researched cam- you can get pretty good performance out of a 307. Certainly not race car performance, but good streetable horsepower, without the high dollar pistons for compression.
A very well respected race car owner/builder/parts distributor in my area once told me to build a 307 over a 350 for a circle track dirt Chevelle I was racing. His idea was "stroke the hell out of it" for more torque and HP. I was already well into a 350 build, so I didn't heed his advice. But if I had to do it again from scratch I would have followed his instruction to a T.
There was a recent article in Super Chevy where they built a 307 and got respectable performance out of it. Check thier archives.

 

Still say he should buy a new top end and bolt it on IF the bottom end of the 307 is good-to-go.

 

Casper take the 307 for free and sell it for as much cash as you cane get. Put it in a savings account and keep on saving you're money for a 350 / 383. I agree with the rest of the guys. Fixing up that 307 is like chrome plating a dog turd. It will look good but it still is a turd. Long term you will be much happier with a 350. They make lotsa power and parts are relativly cheep amd plentyful IMO.
Good luck!
Mike