Puttin' Perfume on a Pig...307 Tech?!

The local dirt track in Ga started a pure stock class and used a 325 cu in rule. Most Chevy guys ran 305's.
I built a 307 for a young guy. .060 over 4 eye brow flat tops, Chevy 929 cam , which was required by the rules. Cast iron Q jet intake. 993 heads. It pulled harder up off the corners than anything else in the class and he won the championship. 307's can be made to run fairly well ,fairly cheap.

 

Yes the block is a 194 casting with recessed oil filter boss and the relocated z bar pivot hole. And I stand corrected it’s a 250-300hp 327 cam. The info on the camshaft came from a list of factory camshafts and spec I found on the internet. I input all the info into Dyno 5 sim software with the proper spec for my 283 and it produced the HP as Chevy advertised, also did it with a 327 using typical info for a 327 (462 heads with 1.94/1.50 valves, 64cc chambers, standard intake (4bbl @ 600 cfm = 300hp, 2bbl @ 400 cfm = 250hp) and exhaust for the time period. I got the same results, same HP for 327 as Chevy advertised. Also GM did use the same cam in different engines as they did with all cams except special cams such as the 375hp/327ci, the so called 290hp/302ci and the 283hp/fi 283 ci, to keep cost down and as we all know the same cam will produce different results in different engines. The other thing one must know is that old GM specs are @ seat to seat duration not the typical +0.05 that cam manufactures use today. Yes 300 degree duration sounds long but think about the advertised durations of most cams today many for street purposes are advertised around 270 to 280 for street use so the duration really isn’t as long as it sounds once you realize it is seat to seat and not at +0.05 lift. Also it is a low lift but the Vortec heads were designed to work best with low lift cams and need machining to work with anything over .45 lift and most articles agree that 0.42 lift is stock cam lift which I can get with 1.6 rockers on this cam. That list of cams also had the stock cam for a 68 307 @200hp, I also ran it with standard heads, intake and exhaust and got the same results as advertised by Chevy. Then ran that same 307 and cam with 462 head 1.94/1.50 valves, 64 cc chamber, 4bbl intake and hp ram horn manifold and it produce 260hp in the program. The link is the link to the list from grumpys garage, you will noticed the PN 3732798 is for 62-66 283 and 327, this the cam I have, PN 3896929 is used on 67-69 283, 307, 327, and the 350, these are the cams I used to test my results and I got identical HP as show using the correct components from that time period. Also keep in mind the program documentation states that results vary by +/- 5% and are based on the info input. I take this with a grain of salt and figure that +/- 15% or more and if you input garbage it will spit out garbage.
https://goo.gl/images/PKhKHt

 

I raced in a claimer class so we sought out good used engines. The 307 was what we looked for of a 350 wasn't available. I'd buy wrecked cars or my junkyard sponsor set a few aside for us. A good low-mile engine would wake up with a cam, intake, distributor and carb that we moved from engine to engine.

 

Interesting read. Last time I thought about a 307 was years ago when all I heard was the off the hip rumours that they are junk. Never gave them much thought. I had one in 70 Camaro. Put in a 350 and sent the 307 to scrap.

 

Probably still running good too,

 

I saw your post on SNS, looks like you took their advise and came back here.
You may know this already but the sale of that Nova 283 block could help finance an engine build that would produce those hp numbers that the "digital dyno" spews out.
Seems to me the time researching on the internet and typing all this could be better spent on making the money to build a "real" engine(sorry Vicky).
As @31Vicky with a hemi says; 307's are (capable) of being built into dependable, reliable (and extremely boring) engines.
I just don't see the point other than the challenge of saving money by using a bunch of parts because you already have them lying around.

 

Hi
Back in the old days every one wanted 283- 301-302-327-350-396-427-and then the big one 454.
You would never say you had a 307 going thru the muscle car era. Now many years later all first gen small and big block chev can be built as good running engines. It is up to want you want. Years ago there was a test to see what is better the 350 or 383 the result was close to the same. Just my opinion
Regards
Dave

 

I have a 69 C10 with a 307 stock. What is the best head to get? And which cam would you all suggest using? Also a random question. I've been told to put 305 heads and a 350 crank to get some pretty good power out of it. Is this accurate?

 

Heads from a '76-'77 305 4-bbl motor....
Those have 57cc chambers and 1.840" dia. Intake valves with 1.500" exhaust valve diameter..
I'm sitting on 2 sets for future builds...
Oh, and keep the 307 crank!!!!
Those are the same as the 327 cast cranks...

 

What piston would you use to get the correct pin height to use the 3.48" crank with the 3.875 bore ? and the rest has been covered here more than once. JW

 

What do you think of just changing the cam intake and carb and leaving stock heads for now? Would I get any kind of power with that? Not really looking for a hot rod. Just a daily driver with a little punch.

 

The 305 HO heads are what you want mid 80s. the 305 truck and van heads are almost the same, early 305 heads work well too.
Do not bother with a 307 if you don't want to change the heads. The changes need to come in a package. If you want a 350 build a 350.

The compression height would be dependent on rod length as well.

 

Is there a specific casting # identifying a 305 HO head?

 

I haven't actually found a set of heads yet. Wanted to see what the opinion on that combo would be before I started trying to find some.

 

14014416 aka 416 are the HO heads

14022601 aka 601 are a good find as well
(but don't mix it up with 67-68 heads) and


Avoid these numbers unles you own a machine shop

• 376450 have 1.72" intake valves
• 354434 and others are 2 bbl heads, and have 1.72" intake valves. Best to just avoid these altogether since other, better heads are readily available.
• 14102187 Swirl port heads used on some 305 TBI engines
• 10110810 1986-'91 swirl port

 

Awesome. Thanks for the info!!!!

 

Not hard to find either, are usually socheap as well.

 

Any ideas on where to start looking? I've looked on CL but can't seem to find any

 

They might not be everywhere you're looking and your profile doesn't include a location or region so it's hard for others to help.

$100
https://akroncanton.craigslist.org/pts/d/sbc-chevy-305-ho-cylinder/6439439220.html

 

Oh sorry! I'm new and haven't figured all that out yet! I'm in SC but might try to contact to see if they would be interested in shipping!!

 

I miss Fat Hack

 

I built 2 307's bored to 4 in bore with used L82 pistons 350 crank, sold one of them to an older guy for a pass car of some flavor, the second one I built for my own destruction engineer 16 old son, he failed to destroy the 307/350 in the 3 years of attempted destruction. Associated parts i.e. 350 transmissions 7.5 rear ends and many U-joints didn't quite stand up to the after school rigors. I'd not waste my money again unless I had a bunch of standard forged L82 pistons laying around.

 

A 4" bore and 3.48 stroke is a 350, not a 307.

If I take clay and make a vase, I have a vase, not clay
If I take a piece of sheet metal and make a 1/4 panel I have a 1/4 panel not a piece of steel.
If I Machine a block and parts into an engine with (4" B X 3.48 S) I have a 350 engine.

 

A 307 bored out to a 4 in bore is the only good use of a 307, that's happen to be my point.

 

Racer's BS. "Look at the casting number's"

 

Another random question. What about aluminum LT1 350 heads on a 307? Found a set for 200

 

Doable but not worth it.
Might be better to put some 427 ford SOHC heads on it.
It's a 307 and not worth a bunch of effort.
Well tested and proven combo.
Start with a good short block - (cheap)
Add some 305 ho heads - (cheap and bolt on)
A nice 262 cam
Intake without huge runners
Exhaust with not huge tubes or pipes
Over 300 HP of fun from throw away parts for dirt cheap.
Don't overthink it. Don't think you'll be a rockstar at the dragstrip either but it's a damn fun engine.

 

Lt1 reverse flow cooling and not that good of exhaust flow (even lt1 guys prefer the cast head) 96-00 vortec heads are based on the lt1 for standard flow cooling they are known for cracks tho

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307 are under rated had a nice one in a 68 Biscayne with 4 speed 300 double hump heads holley 4bbl and i think a 292 cam

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Thanks, epay shows a few 14014416 heads and some come up as Mercruiser which is odd because I have an old 305 Mercuiser engine. I wonder if there is a difference between a passenger car and a boat casting?