Just picked up a complete stock 307, cast # 3970024. I have done a little bit of research, and while just about everybody says its a boat anchor go 350. It's hard to pass up the chance to build a free 307... I read an article on SuperChevy.com and they picked up a 307 did some mild bolt on and dynoed it at 315hp and 330tq and were able to stay under a pretty small budget. All I was wanting to do was get a 300hp engine under my RS. Is it worth going this route since it is a free motor, or should I try and sell it and just buy a 350?

Hell the 327 crank that came in the motor is worth money alone... Wonder if I can at least do something with that?

 

hate to repeat this,but sell the crank and build a 350.

 

Free doesn't mean much if you need to spend more to reach your goal than it would take to just build a 350.

 

EVERYONE says 350 for a reason. In the end you will have 43cu.in. more, whatever extra power that equates to, and all the parts cost the same.

 

350 lol..ill stay on the bandwagon

 

They cost less, and there's a much better selection.

Don't count the 307 out, though.. there's LOTS of things it's good for...

 

Wow, I really like the idea of turning it into a table. That is kind neat actually! But in all seriousness, I'm just going to take it to a machine shop or a scrap yard.

 

If you had a V6, then I could see working with a free 307, assuming it was good as is, and all you needed to do was drop it in and go. I had a 70 Malibu with the stock 307 a long long time ago in a galaxy far far away ... and it was no muscle car, but was a good little motor. But given you have a 305 already ... I'd make the table

 

For free? You'd be foolish to let it go. The engine is a small-journal small-block with a 3.875" bore and 3.250-inch stroke. The turbo buick guys would kill for that type of freebie, especially with those engine characteristics; two more cylinders than their LC2 with better flowing heads. I would go with a forged rotating assembly, fuel inject it, then turbo charge it....

 

Ummm .... no.

It's a large journal block, with a cast crank and dished pistons.

There's a REAL GOOD REASON it was free; and it WAS NOT because, it's in such high demand.

Nobody wants a cast 3.25" crank.

 

.... and? Like I was saying, it is perfect for a boosted application. Even with a large journal block, that won't hinder anything as even the 68/69 302's were large journal. Dished? Perfect for boost. Cast? Every LC2 that left the factory was cast and were tuned for 15-pounds of boost. The 307 engine is free, with essentially the same bore as the LC2, and same stroke as the 2JZ. Why would boosting it be a bad thing?

Not everybody runs naturally aspirated....

 

Well I have a few people interested in buying/trading for it. So we will see where this goes...

 

Because you could boost a 350.

 

True....

 

Rebuilding that "free" engine will cost more than going to the junkyard, BUYING a 350, and rebuilding that.

And then, you have just spent MORE money, but got LESS motor for it.

Same argument for "boost": given that THE CORE is invariably the cheeeeepest part BY FAR of any build; and the more money you spend on stuff outside of THE CORE, the less THE CORE amounts to proportionally; it makes NEGATIVE sense to spend the time money and effort "boosting" a 307, when for the EXACT SAME time money and effort, you could be "boosting" a 350 instead, and getting nearly 20% more to show for your time money and effort.

I'll paint a picture of how bright that is:

So you go to the grocery store, and you've got $5 to spend. You look at this nice juicy steak, and it's $5 a pound. So you walk up to the counter and tell the butcher, yeah, I'll have $5 worth of that steak; but since the package is "free", only give me 14 ounces of it, instead of a whole pound.

Now, wasn't that a GOOD IDEA?

That's what building a "free" 307 is like, compared to building a $50 350.

68/69 302s were .... 302s. They weren't 307s. Not applicable to the matter at hand.

LC2s were ..... LC2s. Not 307s. Again, not applicable to the matter at hand.

That "free" 307 is GARBAGE. Somebody probably couldn't figure out a way to get rid of it, and thought, hey I'll just give it away, somebody will think they're getting a good deal, and that way I won't have to deal with something the garbage men won't take. Basically the OP now has a disposal problem on his hands; NOT a "motor". It's a bunch of weak 2-bbl bottom-of-the-line GARBAGE that nobody wants.

 

Now that's just cold...

A 307 block won the first Engine Masters Challenge. Oh, they were displacement-limited. And he stroked it.

There's nothing special about a cast 3.25" stroke large journal crank for boosted applications.

A 307 is 2-piece rear main seal and flat tappet cam. Both downgrades from your current 305. It does have a slightly more beneficial bore/stroke ratio than your 305, but only slightly. Oh, the heads have soft valves & seats, and the ports are horrible (swirlport 305 heads are better in all those respects).

There are times when the most expensive route to a final goal is starting off with something free. This is one of those times.

 

I threw the 307 up on CL for cheap just to get rid of it and make some extra cash. The first person to get a hold of me was an older man who was looking to restore his 69 Chevelle to its original condition. And he wanted my motor because that is what I guess came in his car. And that is not what he had in it when he bought it. Instead of offering me the money I was asking for the 307 he offered me the old engine out of his Chevelle. Which happens to be my favourite sbc engine of all time, the one motor I though I would not be able to afford or find. A 67 327 only thing wrong with it is he had to sell the heads/manifold/carb off of the 327 to help pay for restoring his Chevelle. SO.... I'm trading him straight across the 307 for the 327 long block.

Now we all know what's is going into the Camaro

 

I wouldn't take that trade.

 

Use lotion. Then a cold shower.

 

why not?

I doubt he could even make $100 off selling the 307. But people will still pay for a 327. Im looking at only potential profit here. 327 is worth more cash then the 307. I say it is a great trade.

 

you're not getting a long block

 

Thanks for catching that, I really should proof read my posts before submitting them. The 327 is a short block, and the 307 I have now is also a short block. I don't see why this is a bad trade... Especially when I want to build a 327 in the first place. Now before the pissing contest starts on the whole 327 vs 350 and why I should go 350. I want to say that I wish to go with a 327, not a 350 or 400. I have a chance to trade junk for gold in my opinion.

 

Built a 350/383, tell everyone it is a 327, you win twice for getting more power for less money and you tell everyone it's a 327 so you can get that fantasy out of the way.

 

Man, I am just trading my way up lol. I now have the 327 sitting on my engine stand in the garage, when a guy I work with found out about it and offered to trade me his freshly rebuilt 400sb short block for my 327. So I will be doing a straight trade this afternoon for the 400...

 

why would someone do that?

 

one more thing

you've taken this subsection of "engine swap" to a whole new level; it's now engine swapping

 

See if you can get to an LS9.

 

shhhh. because they are better, duh.

It is all a mindset. It is all due to a perception.

Most of which is the same people that want to throw a 3/4 cam in it with a 750 dp double hump heads etc. Living in the past.

 

What heads should I use on tue 400??

 

What induction are you going to use?

 

I already have an Edelbrock performer intake, and a 650 Holley double pumper. Figured I would go with that, oh and the 400 already has a 302 cam.

 

What is that?

I have difficulty recommending factory heads for pre-'87. There just weren't many good 350-400 heads back then.

First thought is "Vortec 062 or 906". But, then you wouldn't be able to use the intake manifold you have.

 

^^that actually isn't a bad thing...that performer intake is going to choke a 400ci engine

 

Yeah, I just picked up some Chevy 350 Vortec heads out of a 99 Chevy Z71 truck tonight not a bad price either. So I'll probably order an Weiand Stealth Vortec manifold next and use a 650 Holley double pumper. I'm thinking a 650 will be big enough, or should I be looking at 700cfm?

 

Since you plan to use Vortec heads I would say the 650 is good.

 

Cool, and I think I should have that IM ordered from Summit tomorrow...

 

i believe you'd see benefit from a carb as large as 750. but a 650 will have outrageous throttle response

 

Will I have to modify the water ports on the block to match the ports on the heads? Or will it be a bolt and go deal?

 

you may have to drill steam holes in the heads, but any machine shop can handle this for you. i don't have any experience with the gm 400 sbc

 

Yeah, I'm new to the 400 as well. This motor is not going to be put together over night and swapped in. I plan, research, and make sure I have every part needed and every part modified to fit perfect. My goal in building motors is to always have it fire the first time... I'll read around and do the research I'm sure I'll figure it out.

 

Good choice on the heads. Have the proper work done to them and they will work great for what you have. My understanding is that you will have to have the heads drilled for the steam holes. But like mentioned earlier, any machine shop worth anything will be able to do that.

 

Thanks, I'm really excited about this project. And for all of those wondering they are the 062 heads

So when I go to have the machine shop drill the steam ports on the heads, what head gaskets would I use as a templet??

 

A 400 head gasket.

While Vortec heads flow well, the valve springs are terrible, and valve lift is extremely limited for aftermarket cams. If you're having a shop work on them, have them cut the tops of the valve guides for positive stem seals, which will allow better springs to be installed, and increase valve travel.

 

Thanks I'll look more into that so I understand the process and know what I'm talking about. Any articles on here that explain the process?

 

To my knowledge there arent any on here talking about that, but it is a simple process.

Any shop should know what they need to do to the vortecs. Do just like 57kid mentioned and have the guides cut down. Of course the spring will need to match the cam you intend on running. Go ahead and have them install screw in rocker studs. Vortec's flow starts to drop right above .500 lift on the intake in stock form.