1940bowtie

Great Site! I have a '68 Cutlas Conv. orgi 350 & #5 heads. Heads are currently receiving 3-angle valve job, surfacing etc. Also just received Performer RPM intake and 750 cfm Edel carb. I would like to build "nicely" performing street cruiser. This car wont see the strip, but it will see lots of Hwy miles. I recently read an Edelbrock article "397 HP in and Olds 350" that peaked my interest. I am concerned that the cam might be to radical for my application. The cam (#7112) has duration @.50 of Int-224, Exh-234, and lift at valve of .496/.520. Anyone have any experience with this cam or thoughts? I'd like to get around 350 hp and still afford to drive it everyday, or am I dreaming?

70Wcars

That is a bunch of cam for a 350..if you currently have power brakes you won't after installing this cam, not enough vac. That much cam would also require more stall speed in your converter and lower rear gears to perform at its best. Try the 214/224 cam for better street perf. and still a rump to the idle. If you install it yourself use a high quality timing chain and I always degree every cam in order to get the most out of it. Nothing more frustrating than to install a new stick and have it several degrees retarded only to have the car feel sluggish out of the hole. A couple of degrees of advance will pump up bottom end torque, and that is what you want in a street car.

1940bowtie

Thanks a ton for the reply... I'm definitely going for routine street use. Sometimes its hard to find someone willing to share thier knowledge. As I recall most of the roller chains I have seen have preset notches at 4 degrees, is that to much? Also is the Performer RPM intake overkill for the 214/224 cam, most of the articles I read seemed to imply that the regular Performer intake is not any better than the stock '68 manifold. Your post footer lists two 70 442's... driver & strip car?

Huron

1940 bowtie,

That is a lot of cam. You didn't mention what transmission you have, but if it's an automatic, you going to need a high stall converter/and/or 3.73:1+ rear gear or you will have no low end torque.

It seems to me that if you want a pleasant street ride it's best to try to achieve your hp goals by building the engine with an excellent cylinder head and a mild cam, rather than using a mostly stock head and trying to make the power with the camshaft.

For your goal of 350 h.p. you should be able to achieve that by using a cam with less than 220 degrees of duration all the way around, and keeping lift below .475". Plan on building with 9.5:1 pistons. Call Crane and tell them exactly what you want to do. Once you get the cam specs, then call Coan or one of the converter mfgr's, and get a converter made for your combo. Get your distributor recurved for your compression ratio/cam/converter combo. Install a Performer RPM intake and a fresh 750 cfm Quadrajet and you should have a pleasant street machine.

Huron

70Wcars

Huron is spot on with his reply. Build a combo that is drivable at street rpm's and you will enjoy it much more. As far as the Perf.RPM, it is a great manifold and should work well with the slightly smaller cam. The reg. performer is great for weight savings over a stocker.

Yep...two 442's...one a 4-speed numbers match car that we take on cruises etc., and the race car that I can flog and experiment with combos...like cams and intakes LOL.

DLamb04

Is it true that Olds never did big or small block. And does that mean then that a 455 Rocket is the same block as my 307 (i think that's what it is). Im so confused cause i have a 85 Cutlass Salon, Vin Code Y, 5.0. I wanna medium build 350-400 horse. Not sure where to start. Do i rebuid and yank the computer, and emission strip it. Do i get a 403, I'm so confused on where to start. I heard Olds 350's, are good relible engines. But what's gonna be easier to get parts for. I don't have an endless pocket book but refuse to do anything less than right (I'm gonna show it, eventually). Thanks for any and all help.

I'll post photos soon
Donavan

GoldOlds

Olds DID have a big block and a small block, although the difference wasn't as drastic as big block Chevy vs. small block Chevy; basically, the only differences are a taller deck on the big block (about 1.3" or so) and bigger main journals on the big block (3.0" vs. 2.5"). Even the heads are swapable, although you'll lose compression by putting BBO heads on a SBO. The 403 is a good engine if you can find one with clean cylinder walls; you can't do anything to the block other than sleeve it because of the huge factory bore. The Olds 350 is a good, reliable engine; try to find one pre 1973. It's possible your Cutlass has a Chevy 305 (also a 5.0 litre); if the oil filler tube is front and centre on your engine block, it's the Olds 307. Also, Chevy distributors go through the intake manifold; Olds distributors do not. The big blocks will fit in there too, I think - the 425 is REALLY sturdy, but the 455 is easier to find. A decent running 455 out of a mid 70s wagon will sell for $300 to $400, although many have the performance challenged "J" heads. I'm kinda new to the world of Olds, so most members on this site will know a LOT better than me.

- GoldOlds

DLamb04

Well now i know i have a 307, my oil fill tube is in the front center of the block. Can i build up my 307. Cam, Gear Drive, do I have or want do something with the crank, what about having the oil journals bored for more oil flow. I just don't know really where to start. Gotta pick a engine would be a good start LOL. I just dont know enough, that id hate to start something and come to a roadblock. I cant afford to waste the money. If theres alot of options I'd like to keep the 307 just bump it up alittle. What advice is there, for me to at least get a game plan. Sorry my post is so scrambled, but I have so many thoughts, and there all jumbled in my head LOL. I wanna emission strip it, so i know i cant keep my heads cause i'll get alot of moisture. so should i go with something like a late 70's 403. I guess the main question is what can i do to a 307 to produce around 350-400 horse, or am i wanting to much.

So Confused,
And thank you so much for your help
Donavan

GoldOlds

I can relate to that! I'm still trying to decide between the current 350 and a 455. I'll be sticking with what I've got until I can sell the 454.
Anyway, go under "Oldsmobile Performance" on this website, click on "Small Block CIDs (1964-1990)" and scroll down to the bottom. There's some useful advice on what you can do with your 307. The Olds 307 is a good, sturdy motor, but you'll be spending HUGE $$$$ to get 350-400 hp out of it. Finding a 403 in good shape isn't a bad idea, although a head swap would be in order; 403 heads are not conducive to even respectable compression. I think some drilling is in order when you do most 403 head swaps; something to do with 7/16" vs. 1/2" head bolts. If you want to get some decent power and NOT spend a ton of cash, find an older 350 with #5 or #6 heads. There's a very good chance that's the route I'll take, since I already have an SBO 350 with #5 heads. I'm considering the Edelbrock BBO heads (less weight, bigger valves) and an RPM intake, which of course will require port matching. If your Salon has a TH350 for a tranny, a basic overhaul (seals and gaskets, might as well toss a shift kit into it while you're at it) should keep it together. The weak link is that rear end. The best bet would be to find a 442 rear end out of a mid 80s 442 (direct fit for your Salon); it has the 8.5" rear instead of the much weaker 7.5" unit; my apologizes if you already know this. As chance would have it, I'm also considering the 350-400 hp range. If I can't do it with the 2.25" exhaust that's on the car now, I'll probably find a 455. From what I've learned so far, it seems that the 455 is only marginally more expensive to build than a 350 and I'm guessing the torque difference will be HUGE.

- GoldOlds

DLamb04

When it comes to Olds I dont know much so thank you. But from what I have been learning (I don't know if it's true), your not gonna want to puy BBO heads on a SBO cause you'll lose compression

Donavan

GoldOlds

True, but milling, decking and/or thinner head gaskets can help compensate for the bigger cc sizes of the BBO heads; pop-up for flat top pistons help too, although that's where $$$$ becomes a problem. I'll admit that I'm hesitant to start messing with decking/milling because I'm not sure which years have adjustable valvetrains and which do not. On the other hand, shims and shortening pushrods are always an option... I think.

- GoldOlds

88 coupe

From '49 to '90, no Olds V8 (except the solid cam 371) was adjustable.

Norm

DLamb04

I think I found out which way i wanted to go with my Salon. Can someone tell me if this is a good idea. First off, I didn't wanna do a 403 cause I was told the heads are crap. So I had to find out why they were crap. Well I did, there crap cause the exhaust valves are to small. I went to a local machine shop that I have used in the past to find out the info. So I asked him what can I do about that. His suggestion was (and he can do the work) I can put some Olds 350 heads on the 403. Put the 403 intake valves in and keep the 350 exhaust valves in. Does that sound right to anyone. I also want to run a roller cam setup. If this sounds like a good idea or any comments that can be givien will be greatly appreciated.

Thanks for your time an knowledge...

Donavan

GoldOlds

Sounds like a good idea, as long as you get the RIGHT 350 heads; just don't use the #3A or #8 heads. While you're at it, make sure you've got hardened valve seats, unless you want to dump a lead additive into every tankful of gas. The biggest problem with the 403 heads isn't really the ex. valve size - alot of Chevy small block guys are content to use heads with 1.94/1.50 valves; those exhaust valves are actually a wee bit smaller than those on the 403 Olds. The biggest problem with the 403 heads is the combustion chamber size; 83cc - that's bigger than some of the Olds BIG BLOCK heads! Still, by using Olds 350 heads, you're getting rid of that problem, so I think your idea is a good one. Most Olds 350 heads have 64cc combustion chambers. If you find a set of #6 or #7 heads, I wouldn't bother using the 403 intake valves; going from 1.995" to 2.000" hardly seems worth the effort. I'm sure someone who knows alot better than me will chime in... Some say the 403 isn't as strong because of "windowed mains" compared to "solid mains" (I'll admit I'm not really sure what that means), but from what I've seen first-hand, the 403 can take a pounding. The other thing to consider is that the 403 heads use 1/2" bolts; the 350 uses 7/16", so there's a bit of machine work to be done there, albeit nothing major.

- GoldOlds