Stock 307 HP ...

[dan2286]

I understand the best route to go is a 350 swap, and that IS the eventual plan. However I am on an extremely limited budget right now, I just looking to get what I can out of it now with cheap improvements. I'd be happy with around 200hp, I'm putting 3.42:1 gears in it next. Eventual plans are for a built Rocket 350 backed up to a TH350 transmission.

John

Since you are going to be putting an Olds engine in there, everything you do to the 307 will most likely transfer over to the 350. I dont know how tight your budget is, but I think the best place to start would be with headers/exhaust and getting rid of the emissions system. That would involve getting a non computer controlled carb and distributor. Doing this stuff wont get you to 200 H.P., but it will make the car a little more powerfull especially with the gears.

 

[Blake442]

If all you want to tide you over till you get a 350 is a little improvement then I would just go with a set of headers, and some true dual exhaust. Leave your stock carb and dist. in place for now. Do a tune up on it and then just drive it.
Yes, all of the stuff that can go on a 307 will carry over to a 350, but honestly it's not worth your time. Enjoy the car and save your pennies for a 350.

The reason nobody builds up 307's is because of their limited potential. All of the parts and money that you would put into the 307 to end up with a mild motor would go much farther in a 350, 403, or better yet, a 455.

 

[olds307 and 403]

Their heads are the problem, the exhaust especially. No one makes performance heads for small block Olds. Even 330 supposedly overlap the small 307 bores. You can just throw small valve Vortec or fast burn aftermarket heads on a 305 and good power. The big bore Olds 350 and huge bore 403 are different stories. You can use decent factory heads or big block heads on them. There are the FCR fast burn heads that are pushing 400+ cfm intake for the Olds now available. Of course there is a huge bunch of BS going on and these heads may not be around for long 😢 .

 

[86 CN Cutty]

reply

STL84Calais

I'm sure it's still cheaper to install a larger displacement engine but I think this is pretty cool.

http://blogs.popularhotrodding.com/6304 ... index.html

 

[kustomkyle]

even if ya rebuild the engine you will never get more than about 350 horse out of it. my buddy rebuilt his 1895 442 307 to the nines.........and they tweaked that sucker as much as they could. dyno'd at 330 horse.

still a vast improvement........but not up to the 400 to 500 horse guys are kickin out now


peace

Since no one has really answered the original question, maybe you can elaborate what exactly went into that 307.

Seriously, 400+ horsepower is realistically too much for a car that is to be driven on a regular basis. Yes, people have gotten 1000+ horsepower to be streetable, but such engines are built by high end speed shops very precisely and cost who knows how much to build. It's easy to make power out of a 5920CI monster big block huffed and stuffed with no exhaust. Consider fuel mileage. Emissions testing too.

With 400+ horsepower you would have to change/modify A LOT of stuff to keep the car on the street. Brakes, suspension, rear axle, transmission, etc. etc. etc. I guess that is fine if you have a lot of money to throw around and have a fully equipped shop to do all the work.

Of course it is cheaper to build a Chevy or a bigger Olds to make tons of power. But how do you get the most out of what is already there? 442 cam/valve springs? Headers? Tweaking the carburetor? Dual exhaust? What else? I know few people even bother to even rebuild a 307, but???? I'd rather have something fun and drivable than just bragging right about "I've got the most power".

I don't think 307 is that worthless, you just can't put a blower on it and throw $1000's of endless speed parts at it. Kind of like the article link above. Ingenuity. I do have a Popular Hot Rodding magazine from 1990 that have a Mondello build up of a 307. The main thing I remember they did to it was put a 350 Olds crank in it and strengthen the bottom end.

By the way I am not trying to offend anyone. But I am tired of reading magazines/etc. where someone takes the time to write in and asks how to make more power out of an engine, and the only advice that is ever given is to swap the engine for something bigger. Anyone could tell you that.

 

[STL84Calais]

Like I said eventual plan is a 350, but how about something like a procharger on the 307? Stock heads could handle like 8-9 psi boost right?

 

[beeterolds]

its not the heads you need to worry about its the bottom end!! and when you say 350 please dear god i hope you mean Olds 350!! its a direct bolt it!

The stock Vin y 307 puts out roughly 140hp net.. with all the accesories on and in place.. If you really wanna get the most bang for your buck.. do a 350/or 403 Olds.. hell i put together a 455 for my car.. and it cost me less than a $1000.. just gotta know where to look 😉

 

[Blake442]

Seriously, 400+ horsepower is realistically too much for a car that is to be driven on a regular basis.

Hahaha! Where on earth did you come up with that idea??
Are you forgetting about the dozens and dozens and dozens of different cars that have come from the factory with more than 400 hp?
I know a fellow that is the original owner of a '70 W-30 442 (390 hp/510 ft. lbs.) and he drove that car every day, year round for 15 years, stacking up over 250,000 miles, and even used it to tow his 25 ft. boat. Doesn't sound like it was too much power to me...

Stock 307 heads don't flow for sh*t unless you were to port the living daylights out of them.

Yes, while it is true that if you put in the time and effort, you can make decent power out of a 307. But you can't do it without removing it from the car and doing some serious work. So here's where the conflict arises. If the motor is already out of the car, all that work put into a 307 to net lets say, 300 hp for a benchmark number. Well, fact of the matter is, a 350 or 403 already has that much power in stock form, and all the same work you'd put into a 307 to get that 300 hp figure, would probably result in a 350-400 hp motor if you started with a 350 or 403. Do the same things to a 455, and you're in the 400-450 horsepower range. See where I'm going with this?
It's not that everybody is saying that it can't be done, we're just trying to save him some trouble cause it's really not worth it. He already expressed his intentions of a 350 swap later down the road, so he might as well save his money. If you wanna build up and 307 to be different, then do it up, but in all honesty, your money would be better spent on a different motor.

 

[kustomkyle]

I guess I just meant that I wouldn't want to drive something with that much power everyday. Too little power takes away from the driving experience, but so does too much, as in with either it can be a challenge to drive in traffic. If done right, a powerful engine could be very streetable. but also, for peak performance, gearing can limit you too. It is also important to remember that you can't expect to just drop in a high horsepower engine and expect the factory transmission and 7.5 rear axle to survive with at least some tweaking either.

 

[Blake442]

I guess I just meant that I wouldn't want to drive something with that much power everyday. Too little power takes away from the driving experience, but so does too much, as in with either it can be a challenge to drive in traffic. If done right, a powerful engine could be very streetable. but also, for peak performance, gearing can limit you too. It is also important to remember that you can't expect to just drop in a high horsepower engine and expect the factory transmission and 7.5 rear axle to survive with at least some tweaking either.

I think you'd be really suprised as to just how 'streetable' a 400+, 500+, or even 600+ hp car is...