majcutlass

I have a 1988 cutlass supreme classic brougham with a (80-84 block casting 3161) 307 that uses flat tappet lifters and 5a heads in my , The original engine is a (85-90 block casting 4790) 307 with roller lifters and 7A heads. I DO NOT WANT 7A HEADS! My question is can I use 5A heads on the 85-90 roller engine as a direct exchange and no adjustments. Also do anyone know where to purchase short blocks? All comments welcome. Thanks Mike

Redog

No in 85 the ports on the manifold got smaller and it only accepted 7A heads

joe_padavano

Of course, if you swapped the heads AND the manifold, you'd be fine.

Redog

True but IMO it's not worth buliding a 307.

The 87 442 had a HO 307 motor, also known as the "9" motor which had a bigger cam and a few other goodies which got the motor upto 180 HP. That might had been awesome in 1987, but it's not 1987 anymore.

Your best bet is an older motor. You can pick up a SBO or a BBO and they will drop right into the engine bay with on probelms. The 455 is about 2 inches taller, so just keep that in mind.

I dropped in a 1968 Olds 350 and a TH400 trans. I paid $420 for the combo and it cost me about $800 in parts and helping labor to drop it in. I did do a lot of the work myself.

With this motor in the Delta, the car ran 15.5 in the 1/4 mile when it got traction. I avg'ed 15.8 feathering it on launch. Hell of a lot better than the 20.65 @ 64 it ran with the 307

majcutlass

Thanks guys, race power isn't what I was looking for. It's just I stumbled across this log and wanted some input. I have a 307 roller sitting in the shed, and was looking at pulling the non-roller out and using the top end (heades and intake) on the roller. Thought the roller would give better response. What you think????

rccktmn2

I have to disagree. If you've seen the popular hot rodding engine masters challenge, this year there was a 307 olds with cast iron 5a heads running almost 400 hp with a solid cam. The 307 is worth building if you want the stock appearance of the block and numbers.

easytobedead

yes an that is the rout i will be taking! I do not mind putting money in the 307!It would be diff from a 350 an a 455 running 3-400 hp.

J-(Chicago)

Psssh, I wonder how much time, money, and effort went into that 307. I'm willing to bet too much, even with all of BT's experience and knowledge factored in.

easytobedead

but come on a 307 with 400 hp !l i like the 307 much more then the 350. I would want my 307 pushing 325hp.

J-(Chicago)

Start saving your money then bud. Once you get 4 grand, you will probably be about halfway there.

Warhead

And a 403 will be a better street engine than a 350.
I agree with J.
Build a 350 over the 307.
The only reason Chevy guys EVER build a 283 is for a #'s matching restoration.
They are more expensive to build, and can never make as much power as their larger brothers.
Some guy's want to build 260's also.
Strip the engine for pieces to build a bigger one.
Scrap iron will give you 7 cents a pound. THAT is where the 260/307's value is at.
A 307 gives up 100 hp compred to a 403, due to the bore size.
Fact of life.
Every day of the week.
Twice on Sunday's.
And 3X on your birthday.
JMHO,
Jim

rccktmn2

I don't think it was anywhere near 4000. Stock 5a heads, solid cam, .060 over, 10:50 to 1 compression, I did notice a milodon oil pan and a bottom end girdle. Either way you go you can put the same money into a 350 or a 307 and come up with almost the same results. The only way to get bigger results is to move up to a big block but either way it depends on the person building car.

easytobedead

well.. i am not looking for 500hp. i would like 300-350hp.And if i wanted any thing bigger I would buy a dodge viper!

geckonz08

here are a few options $ dependent

mike
Stage I: Tuning and cheapo-mods (under $100 total)

1. Advance the timing by 2 degrees (to 22 degrees). This may require the use of 89 or 92 octane fuel to prevent pinging. But if you wanna play, you gotta pay. For track-only use you can advance it 4 or 6 degrees, but this makes the car hard to start, and it idles rough.
2. Adjust the secondary air valve spring tension (wrap). On the top rear passenger side of the carb, you'll see a small hex-screw underneath and a small slotted screw on the side. Loosen the hex screw with an allen wrench, and turn the slotted screw out 1/8 turn (hold it as you loosen the hex set-screw) and re-tighten the hex screw. Repeat until you notice a bog when going to WOT, then tighten back up 1/8th turn.
3. If you have a 200-R4 tranny, push the TV cable back (tighter) one click.
4. Install a Robertshaw or Mr. Gasket 180 degree high-flow thermostat. 160 is too cold and could possibly set computer error codes. 180 degrees is a nice compromise, and the high-flow keeps it rock-steady at 180 degrees under all conditions.
5. Add Red Line Water Wetter to the cooling system. All I can say is It really works!
6. Fabricate a cold-air intake system for your car. Using dryer ducting or the stock stuff, get cold air to the air cleaner. Make sure you keep the hot-air riser tube or cold weather driveability will suffer. If you have a dual-snorkel air cleaner, wire the second snorkel to open when the first does (use a vacuum T) and get fresh air to it. At the track (or even when the weather is warm) just disconnect and plug the hose to the second snorkel, so it's open all the time. Good places for fresh air are hard to find on these cars, but you can use the hole behind the passenger's side headlights, in the fender up there, or go underneath the radiator support.
7. Get a K&N air filter to replace the stock one. K&N DOES make one, you might need to supply your speed shop guy with the AC filter part number to cross reference by, rather than by application.
8. If you have a single exhuast (and not the duals provided with H/O's and 442's), then replace the single muffler with a turbo style muffler. Hollowing out the catalytic converter would provide a benefit too, but since most areas check emissions now, and since it would be illegal, I wouldn't recommend it, and I wouldn't do anything like that myself.
9. Get some richer secondary metering rods. The Olds FAQ at http://www.442.com lists some recommended rods under the Rebuilding, Quadrajet section. Only way to find what rods are right for you is by trial and error.
10. Check to see that your secondary air valve opens fully. This isn't an issue on the H/O, but on some other 307's it is.

Stage II: A few more bolt-ons (about $500-$600)

1. Get a performance computer chip. I recommend having a custom chip made if you can find someone to do it. Try about 8 degrees additional advance (i.e. in addition to that in the stock timing tables) at WOT (plus the 2 more you added to base timing in stage I makes a total of 10). Second choice would be a Thermo-Master chip from Hypertech. These only advance the timing 5-6 degrees more than the stock chip (and only at WOT) and are very streetable. The Street-Runner version barely advances it enough to notice.
2. Add a dual exhaust system. Hooker makes a nice 2.5" system (see mine). Walker makes a 2 1/4" system for about the same price, and the original GM system from the H/O, 442, and GNX is still available from GM for not much more. If you're only running at the track, forget this step and just disconnect your catalytic converter from the exhaust system and run with an open pipe.
3. Upgrade the ignition system. Spiral core wires make the biggest improvement (I use Taylor Spiro-Pro). An upgraded coil (like Accel, Hypertech, etc) will also help a little.
4. Install a shift-kit in your tranny, and get a tranny cooler. I like the B&M supercooler, it has a low pressure drop and is small. Put it in line before your stock cooler. Braided stainless hose or custom bent hard line is a good idea here.

Stage III:

1. Intake. Use an Edelbrock Performer Intake. Can't use this with 7A heads. It bolts into place, but attaching everything back up isn't exactly bolt-on. You'll need to move some sensors, get a few pipe-adaptors, modify the throttle cable and TV cable bracket, and bend up a custom cruise control linkage. You will need to re-adjust the secondary air valve, idle mixture, and secondary metering rods after installing this. Be sure to use a 4-hole carb gasket and not the stock 2-hole one or you'll defeat the point behind a dual-plane manifold.
2. optional Partially or completely block off one or both of the heat crossover passages from the head to the intake. A piece of stainless sheet metal from your old "turkey tray" intake gasket will work, with a hole drilled in the center to allow a little air through. If you completely block them off, you'll need to convert to an electric choke. The colder of a climate you live in, the more "optional" this step is.
3. Posi. If you don't have a limited slip differential, now's the time to get one. I found a new GM unit, but Auburn also makes ones that will fit.
4. Gears. Upgrade to somewhere in the 3.23-3.73:1 range. 3.73's are liveable with the OD tranny, but if you do a lot of driving at 70+mph, consider something in the lower 3's. Don't forget to recalibrate your speedo!
5. OD tranny. If you don't have one, get one. Try to find a core from a 442, H/O, GN, T-Type, or Monte SS. Give it a good rebuild with a quality kit. Some kit and rebuilder recommendations can be found on the GN/T-Type home page at http://ni.umd.edu/gnttype/www.
6. High-stall converter. About a 2400 rpm lockup converter should do nicely. These are stock on the 442's and H/O's.
7. MSD-6 (or 6AL) system. Doesn't help power too much, but the car starts easier, idles better, and the power comes on smoother all around. You'll need cooler plugs with this, like the NGK 5670-6 plugs gapped at 0.040.
8. Cam swap. If you've got a VIN Y engine, you can swap in a more radical cam like that used in the VIN 9 engine. Don't go too radical though or the computer and emissions won't like it. You could contact somone like Joe Mondello or Dick Miller to see what they recommend. Remember to get a roller-lifter cam if you've got a roller-lifter engine. Install stiffer valve springs like on the VIN 9 engine at the same time. I also recommend replacing the timing chain or putting on a true roller chain while you have it apart.

geckonz08

ps --Hope it is obvious that the article in the previous post is not mine --I don`t have that knowledge--I am also unsure where I copied it from --trust it is useful
mike

Lady72nRob71

That was from the www.oldsgmail.com site, http://tlentz.oldsgmail.com/ to be exact ("Spicing up the 307", http://tlentz.oldsgmail.com/more_power.html).

Oldsgmail is an excellent source of info on every aspect of the 307 and the G-body Olds the 307s were found in.
Join in on the mailing list and get in with the 307 masters!

captjim

That was Dale's (gmrocket from ROP) 307. He had a post up over there with the details, but deleted it for some reason. Though the heads were factory, there is nothing "stock" about them. I bet he had well over 100 hours in them. Those heads alone would cost a fair amount of money. Like Warhead alluded to, the only reason to run the smaller engine is to comply with some sort of rule. A 350/403 will always be a better bang-for-the-buck, in my humble opinion.

"Either way you go you can put the same money into a 350 or a 307 and come up with almost the same results."

I respectfully disagree, unless you rev the heck out of the 307. The larger bore and cubes will win out, especially on a street car.

csstrux

I have read that article/post someplace before as well. I have also see little mg' triumphs and fiats pushing 600 plus hp through "stock" engines, meaning the original block. I you have the knowledge, time and money, any thing is possible. If that's what you want... go for it, it still a free country... i hope. That said you might be better off money wise looking into a larger mill for a mild street performer.

Warhead

Build a few engines, and drive the cars they go into.
You will never say that again. Cubic inches are literally free power, and torque, on a rebuilt engine, unless the pistons differ on cost. At 1 hp per cubic inch, you are pissing off 43 horsepower, and a similar amount of torque. A larger bore 350 will let even the 307 head flow more air than they can on a 307 block, with NO OTHER MODS. Fact. Ask anyone with a flowbech.

260/307's are good for parts.

Bullshyt.
If you could afford the Viper, you sure as hell would not have the Olds.
You might get a date though.
GOOD luck with it.

Warhead

Dale also used to have a 403 G body in the build section, but he deleted that one too.
STOCK bottom end (he claimed it had 2 cracked head bolt holes, and more wear on the bore than the law allowed- he put in new rings, and bearings on a berry hone), ported J heads cut .060, steel shim head gaskets, 220 cam, RPM manifold was not port matched. Headers, 3500 converter, 4.56 gears, and it ran 11.80's in a mid 80 Cutlass.
He claimed to have over 700 sumthing passes on it.

captjim

I did not realize that he deleted that one. IIRC, it was build pretty loose, and he beat the snot out of it. Wonder what/who upset him? His EMC engine was VERY impressive, especially considering his limited budget. Just a WAG (wild a$$ guess) but I bet it would cost $12,000 to duplicate. It would be nice if he decided to post up the details so others can see what it took to get there. But for half that, you could build a 350 making 450 HP.

majcutlass

Thanks to those that replied to my original post. But I'm sorry this posting has gotten away from it's original intent. Again thanks to those that replied to the original message!
I'm done with this posting.

83hurstguy

$12k??? I highly doubt that. 330 crank, off the shelf Chevy rods, those might have been off the shelf pistons, but I'm not 100% sure. Flat tappet custom cam. That's basically a $3-4k shortblock, with $2k heads. Probably was $6-7k as delivered to EMC with headers, intake, carb, distributor, etc... there weren't that many crazy parts on it at all.

captjim

Gonna disagree with you there, Luke. Respectfully. Did you happen to see the pics of those heads? Lots of work, ported, floors filled, roof raised, intake worked. IMO, those heads would cost you $5000 if you did none of the work yourself. Iron heads take a lot of time. Add in the girdle and machine work, along with blue printing everything, and I would be surprised if you could get that done for under ten grand. Just my opinion, but that kind of work really is time consuming.

83hurstguy

I do agree that the porting was quite extensive, though he mentioned in the end that he could have probably gotten away with a lot less welding on the exhaust side. The intake side was grinding and epoxy, which is a lot less labor intensive.

A full Mondello head porting is like $3k for the labor IIRC... since he did it himself (and never even had the heads flowed), it was definitely cheaper.

If you do the heads yourself, I could see the engine build costing $5-6k. With the heads being completely outsourced, $8-9k.

He made the girdle himself, started with a J+S 5 main halo. I believe the complete girdle setup from Jim is $1k, which includes modding the pan.

I believe he also was planning on putting it in his car to run, which should be quite interesting.

Redog

I'll have to disagree, to an extent

Yes the 403 is 53 ci bigger and there is no replacement for displacement, but the 403 was built with windowed mains where the early 350's were soild mains.

Granted, you'll have to put a lot of HP to break the block, but it is more likey to happen than a soild mained 350. Plus a 403 will have to be built since it was built seriuosly underpowered at the factory

captjim

" If you do the heads yourself, I could see the engine build costing $5-6k. With the heads being completely outsourced, $8-9k."

I agree with that, but when I stated $12,00, I meant just like his with all the detailed work, fully assembled. Ask a shop for a price on a 425 HP pump gas 307 using factory heads, ready to go and I bet it is over ten grand.

83hurstguy

True. We're on the same page

88 coupe

307 with stock heads and a Q-jet.




Bob Dennis, Oldsmobile Calais, 10.886 @ 119.35

Norm

captjim

That's great number, but IMO throwing in what the Super Stockers do is not really comparing apples to apples. Those guys run 1 ring, no oil filter, and many of those 307s are sleeved 350s. Those engines are not built to drive on the street using pump gas, they are usually very steeply geared and built llose so they can rev to the moon.

Oldsguy

That is fast for a car with a 307 though.

captjim

No question. As I stated,
"That's great number,"

83hurstguy

6.20 rear gears and a 5500 stall converter will usually help

rccktmn2

Sorry I didn't mean you would get the same amount of hp and tq out of the larger engine. I know you would get more out of the larger displacement engine and the heads will breathe better simply because of the larger pistons sucking down more airflow. Head up rear syndrome that day.

88 coupe

Yes, with stock 307 heads.

Norm

83hurstguy

If by stock you mean... aftermarket valved with full competition valve job and changed seat angles, some of them being tapped for studs, and running with super stiff springs, then yes. If the car is Super Stock, they are heavily modified.

captjim

We have done the whole SS argument before. It was my understanding that we were discussing a pump gas 307 that was practical to drive on the street. My apologies if I was mistaken. I do not think a SS engine qualifies as most are built to run in a certain (and usually very high) RPM. I stand by my opinion that a 425 HP pump gas 307 using factory iron heads will cost you $10- 12,000, fully assembled.

88 coupe

Stock sizes?

Allowed by class rules, not particularly expensive, and (spring tensions, notwithstanding) desirable mods, for a street engine.

Stock castings. SS rules are less restrictive than stock classes, but the castings and runner volumes must conform to OEM specs.

Norm

88 coupe

Not exactly.

Norm

captjim

Threads have a life of their own, this one took it's course.