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

Underrated?
They are scorned and shat upon.
With just the most basic and standard of Hot rod approachs (heads and cam) they become really nice engines.

 

I built many 307's back in the eighties and always matched them with heads that gave a reasonable compression ratio and always had happy customers. They were all for 4x4's or daily drivers but all were happy with them. JW

 

I’ve always found it interesting how guys will put down the 307 because of its long (3 1/4”) stroke with a 3.875 bore but the 312 Ford had an even longer stroke at 3.440 and a bore of 3.800 and many will rave about their old Y-block.
The 307 is a pig comment is just another one of those urban myths that is easily disproven by a builder with a well thought out combination. A little compression, some head work, the right cam and carburetion will wake up any engine.

 

The 307 does respond to all of the performance modifications, but that doesn't mean I'm going out of my way to find one. Ive built a few for other people and one used angle milled 283 power pack heads cut for 1.88 intake valves and a mild cam. It was impresive. Building a 307 isn't going to save much money because overhaul kits are more expensive. If they were a small journal block with the breather in the block I would would build one, but they look just like a 350. My hot rod/gear head mentality tells me go for the cubic inches, build a 350. Every 307 I've had I've bored to 4 inch. I'm not a hater, I just like cubic inches for performance.

 

The factory design sucked because the engineering end goals were achieved completely backwards and since everything is a compromise the 307 came to buyers as a castrated pig of an engine. Part of the mandate at time was to lower the "AVERAGE" emissions of the entire production line up and namely "Nitric oxide". The 307 in stock form is incapable of producing nitric oxide because the cylinder pressure and cylinder temperature isn't high enough due to low compression. (Heads) The design team figured the best way to lower NO is to not make it. Then they designed the rest of the engine (cam) to motivate a vehicle. A shitty compromise that achieved their goals.

Thankfully, the short block came with flat top Pistons so a simple head swap brings things back to life. Can you imagine if they stuck deep dished Pistons in it, there would be no saving one.

The beautifulest ( is that a word) thing about the 307 is most led a charmed life without ever being too abused. Even though they are running fine , are removed and discarded just for the fact that they are not a 350. That and their reputation makes them very cheap. I've never had to look too hard to find one when I wanted it, used to be tripped over or climbed over to get a more desirable engine. The very key is to find one with a good as is service worthy short block. I won't mess with a 307 that needs machine work because that is a very stupid investment.

If dollars per HP ratio is factor, the 307 with a good short block wins every single time by a tsunami over every other combination you can ever think of. Usually costs about $600 and delivers about 315 hp. Wrapped up in the 600 are a 307 engine, dingleberry hone. fresh rings and bearings, 305 heads with valve job, cam lifters timing chain, gaskets.

 

Your right if you find one out of a car, but they are getting hard to find in my area. I know of 3 circle track racers that use 307 blocks in 360 classes. 400 blocks are though to find now too because of the "roundy pounders".

 

I want to try forged 283 dome Pistons & 400 rods in a 307 block.
Super high compression with water/methanol injection on pump gas. Just to see what happens
Soon as the parts fall into my lap.

 

Not to beat a dead horse but if I put the 416 heads on my 307 what specific cam should I go with?

 

It's been gone over a bazillion or two times.
Set a goal on driving preference
You build a package to reach that goal
Some of these things are up for change and some not.

Engine
Heads
Transmission
Converter
RPM range
Rear gears
Intake
Exhaust
Now pic your cam

 

Be sure and keep us posted. That sounds fascinating.

 

Send me parts

 

I put one together with old 283 heads, a used cam out of a truck, Q jet intake, with an AFB and HEI. Put it in my old front end loader. It runs great.


Sent from my iPhone using H.A.M.B.

 

Hey guys! I'm writing from Chile, south america.
About 4 months ago I bought an 68 Impala Sport Coupe with the stock 307 (here are very very rare, specially 68s)
Im keeping the rear end and puting an overhauld 700r4 transmission.
Keeping the inside parts as is (.040 with flat top pistons with 4 valve reliefs).
I have for installing double hump heads from a 68 camaro (casting 291) with a mild home made porting and sanding.
The cam is a summit 1785 Advertised Duration 274/274, Lift .450/.450
Intake is an Edelbrock Performer EPS
Long tube headers
HEI Distributor

With this parts how much power should I get?
I've heard that some 307 can be bored to 4", I'm thinking of this for the future (casting 3914638 shows 327/307)
Not sure which carburetor to buy yet.

Greetings from Chile!!

 

That is a fairly conservative build, but it should make 250/275 hp without too much trouble.
The horsepower rabbit can be a hard animal to catch but whatever you end up with that heavy Impala will absorb a fair amount of it.
As to the carburator; a simple 600 Edelbrock (electric choke version).
Curious if those "291" heads are 1.94 dia. intake valves or 2.02.
Nice looking Impala.

 

I used to grab up any 307 I came across for the stock cars, and I beat the ship out of those. For it to give any real power, you need to get the CR over 9.5:1 and gear it accordingly. With the 700R4 I'd be thinking of a 3.73 to 4.11 rear end ratio. The Summit 1785 cam is on the mild side but should wake up a relatively stock 307. For a carb, I'd be thinking a Holley 650, if you have a stock Quadrajet, those work good too. Get whatever matches the intake.

 

1.94!

 

A 307 will always be the holy grail a "stroker"…… a 283 stroker.

 

Great read

 

I've been getting a kick out of this guys videos lately, and I ran across this one, and it reminded me of this thread. Even does a dyno run at the end, check it out:

 

Did he ever say what heads he used? Or which cam it actually is? Didn’t catch any of that

 

Not sure, he said they are 305 heads and he mentions a number once or twice, I didn't take particular note. The cam he doesn't say specifically other than it was what he and Lunati settled on for the build with stock heads, and had he known he was going to go with the 305 heads when he ordered it he would've gone with more cam.

 

He did not do anything other than steal an article that someone else wrote. Well if the he in question is fathack.

 

Knew a guy who put a 307/PG in a Vega wagon; didn't do anything to the motor besides a dual exhaust and a camshaft from a 327 he had kicking around the garage. Was a great beater/parts hauler that was pretty quick for what it was and got low 20's mpg just running around town.

 

So I am rebuilding a 307 for my CJ5. I have heads on and was priming the oil pump. Can anyone tell me if the hole in the pictures need to be plugged?

 

An edelbrock carb on a Z/28 intake???....

 

He mentioned they were the 416s.... 1.84 intakes and 1.5" exhaust valves with 58cc chambers....
Compression was around 9.7:1

 

.... Now imagine those heads on a 327....

 

Was there oil shooting out? not supposed to be

 

Yes oil was coming out of that hole. I know later model blocks don't have a tall distributor hole like this block has.

 

Did you try raising your oil priming tool since there isn't an intake present?