Best 350 Rocket Build

[travisbeamon]

I have a 72 Cutlass Supreme with the original 350 Rocket Engine. I'm trying to get as many horses out of it as possible on a $3000 budget. Any suggestions would help. Thanks!

[Bobsw32]

STREET or STRIP automatic or stick gear ratio would help

[stlbluesbrother]

Welcome to the forum.

I'm certan you'll get numerous responses, but I have a quick question others may ask as well - do you want to upgrade with Oldsmobile parts to remain close to original? or are you open to "anything goes"? You'll get tons of responses to the latter.

[Nilsson]

Rip it out and toss a 455 in the hole.

[stlbluesbrother]

I was told if you flip the air cleaner lid upside down (then tighten with the wingnut) you could possibly get 5 more hp. It allows more air to be drawn in. I'm not sure if this is recommended, though, as unwanted debris might get in the cleaner and perhaps the carb.

[travisbeamon]

It's strictly street. I don't know too much all the ratios and stuff like that...the car is an automatic though. The car is completely original. No changes at all. This is the first car I'm trying to build up. I'm open to anything really, I just want that power! I have a 455 I could put in but it's a Buick 455 out of a Wildcat and I was told that the 455s are a bit heavier than the 350 and would cost more in the long run. I've heard that I can get alot more power out of a 350 plus it would be a lighter engine so it would still move pretty good. Again I'm not to sure about alot of stuff, I'm just a newb. I know my friend has a 70 Impala with about 500 horses and I'm trying to get somewhere close to that. I don't want to be last when it comes down to rolling down the hwy!

[Olds64]

The first thing you should do is get some good heads on your 350. I believe teh late 60s 350 heads are more desireable than the 350 head available in 72. Do some searching and browsing on our site and you will see previous posts reference the highly desireable SBO heads.

I also suggest you get an aftermarket intake manifold, headers, and an aftermarket cam. These are all simple modifications that can be done on a weekend without removing the engine from the car. I don't know if you will get anywhere near 500 HP but you will definintely notice the improvement in performance and you won't break your budget.

[cutlassefi]

Originally Posted by Olds64

The first thing you should do is get some good heads on your 350. I believe teh late 60s 350 heads are more desireable than the 350 head available in 72. Do some searching and browsing on our site and you will see previous posts reference the highly desireable SBO heads.

I also suggest you get an aftermarket intake manifold, headers, and an aftermarket cam. These are all simple modifications that can be done on a weekend without removing the engine from the car. I don't know if you will get anywhere near 500 HP but you will definintely notice the improvement in performance and you won't break your budget.

500hp? Yes, that's asking a bit much.

As mentioned a good cam, intake and exhaust will go along way. That's what I did to my '72 350 first time out as well. Ran good but changing the gear from a 2.73 to a 3.73 and putting in a 200-4R made almost as big of a difference. Something to consider.

[redoldsman]

You are not going to get 500hp out of a 350 and I doubt your friends Impala has 500hp. The 7a heads on you 72 should be fine and they already have hardened valve seats. Follow the advice cutlassefi gave and you should be very happy. If you are doing a lot of highway driving, you may want to stay away from the 3.73 gears unless you go the the 200-4R he mentioned. You would be turning a lot of RPM's with a turbo-350.

[Eightupman]

Originally Posted by redoldsman

You are not going to get 500hp out of a 350 and I doubt your friends Impala has 500hp. The 7a heads on you 72 should be fine and they already have hardened valve seats. Follow the advice cutlassefi gave and you should be very happy. If you are doing a lot of highway driving, you may want to stay away from the 3.73 gears unless you go the the 200-4R he mentioned. You would be turning a lot of RPM's with a turbo-350.

I'm pretty sure there are guys with 500HP 350s out there. Maybe on a $30K budget though

John

[70 cutlass s]

You can make a whole lot more out of a 455 than a 350. A 455 and 350 not much different in weight. One thing you have to remember is when you start building up a motor you have to build the trans to match, and have start changing gears to get every thing to work together. 350hp in a small block is easy to make with the right gears is a lot of fun. I had a350 around 400hp I beat a lot cars with it. A small block with 500hp is pretty much a race car and would require a lot of upgrades to every part of the car. And you wouldn't be able to drive it down the highway unless it was on a trailer. Been their done that.

[travisbeamon]

I guess it doesn't really have to be 500 horses exactly maybe 499 will do lol j/k. I just want to get out there and be able to move when I want it to move. I do like the idea of keeping the original 350 Rocket as opposed to switching it out. Any ideas of exactly who makes a decent cam kit for that Rocket?

[Olds64]

There are plenty of great aftermarket cams for your engine. The easiest thing to do would be to buy a kit from Edelbrock which matches a cam to one of their intake manifolds and carburetors; however, if you do some research and asking around on our site there will be plenty of good suggestions.

[travisbeamon]

I've been hearing to go with edelbrock products alot. I take it they are a pretty decent company huh? I ordered a catalog from them a few days ago, I'm waiting on it to get here now!

[jslabotsky]

Pardon me for saying this, but unless your friend can produce a dyno sheet he's full of crap. Or if he is running an honest 500HP, it is unlikely he did it for $3K unless he is a machinist. I guess maybe you could get there for $3K with a Chevy big block, but I'm still skeptical.

Funny how we all have a buddy who has a 500HP Chevy. Weird... I'm sure those Chevy guys wouldn't exaggerate or anything.

People get SO hung up on running a number, be it HP or torque. Wrong approach, IMO.

With that amount of money, here's what I'd do, in order:

• Fresh tune up - set base timing advance, recurve distributor, rebuild carburetor.
• Rear end gears (unless existing is at least a 3.08, preferaby 3.23 or numerically higher)
• Dual exhaust
• Cam & Intake OR High compression heads w/cam & intake. Your compression ratio plays into cam selection.
• Performance valve job
• Headers? Not sure how much they'd help in this application

As far as what the car feels like when you put your foot down, the gears will be the best bang for the buck. Just be prepared for higher highway RPM and a slight hit on highway MPG.

You're not going to be anywhere near 500HP without dumping some serious bucks into the motor, but for $3K you can put together something damned satisfying.

Also at the 500HP level you'd probably need a different torque converter and some other mods too. Kind of need to look at the entire drivetrain as a system in which all the pieces - engine, trans, diff - have to be suited to each other. If you modify the engine beyond a certain point, you'll need to modify other things to get it to perform as intended. It doesn't sound like right now you have the budget for all that.

[Eddie Hansen]

well, I have to agree with what was said, i am dropping a 455 into my 69, it has a 350, number 5 heads and all, it is a 4 speed car, and has 3.08 posi, I bought a 69 455, and have now found a machine shope etc to do the rebuild, I was quoted a little higher then that 3500,
and it will be
bored 9 if required)
new forged pistions
all new internals etc
squared if required
crank cut if required
new valves (larger valves installed0
new cam, valve train etc
oil restrictors,

be on a test stand and tuned etc

and he said an honest estimate will be somewhere around 350-375 hp
and he said do you have any idea what 500hp is like on the street? and i want to really drive my car on the street, not just a street legal racer, so i think I will have a very good set up without all the hassles that come with a motor producing more then 1 hp per cubic inch

[captjim]

Originally Posted by Olds64

There are plenty of great aftermarket cams for your engine. The easiest thing to do would be to buy a kit from Edelbrock which matches a cam to one of their intake manifolds and carburetors; however, if you do some research and asking around on our site there will be plenty of good suggestions.

I am going to respectfully disagree, IMO the E-brock cams are slow and lazy, especially in a 350.

The last 2 posts I agree with, I won't even get into the whole HP thing. slabotsky has a good plan. For $3000 you can get a stock rebuild, barely. If the lower end is OK, pull the heads, intake and cam. Mill the heads a touch, do a good performance valve job and some bowl work. Cr should end up around 8.5 to 1. Get a Performer intake, Q-jet or 670 Avenger, cam in the 210 @ .050 on the intake, small tube headers w/duals and a 3.23 gear. Will it make 500 hp? Not even close. My 9 to 1 355 made 242 RWHP (probably 300 at the crank) ran 13.9 in a 3950 lb car with 3.42 gears, will roast the tires, is responsive and fun to drive. You aren't going to race it, you don't need to get crazy. I can't tell you haw many guys I know that had reliable low 14 second cars that they turned into high HP cars and said that the car was more fun to drive before.

[70 cutlass s]

CaptJim is right on the money that's all you need and 3000 should get you there. I don't know about Edelbrook cams I use comp. cams most of the time and also crane cams. I do know that they make good intakes and carbs. I had a 600 for seven years on a sbc never had a problem. 3.23 are great gears you have good take off and can drive them on the highway.

[jslabotsky]

Originally Posted by captjim

ran 13.9 in a 3950 lb car with 3.42 gears

Maybe I'm showing my age, but I remember when being in the 13s was quick. Those were the days before the LS1, though. That's not bad for a mild build.

[captjim]

Originally Posted by jslabotsky

Maybe I'm showing my age, but I remember when being in the 13s was quick. Those were the days before the LS1, though. That's not bad for a mild build.

A lot of it is just tires. Many of the older muscle cars that ran "Low 14s stock" would run high 12s with slicks and open headers. Think about it too, today's valve job and dual pattern cams were closely guarded racing secrets 25 years ago.

[Olds64]

I am going to respectfully disagree, IMO the E-brock cams are slow and lazy, especially in a 350.

No problem Cap'n. I never said those cams would be great, it would just be a no brainer to buy one of the Edelbrock kits and install it. There are much better cams out there.

I bought a "factory muscle" cam from Comp Cams for my 455. It is the 40068, or something like that. It was used in an early 70s W 31 or something. Whatever it is, I am happy with it.

[AnthonyH'79Delta88]

My buddy has a 350 chev in an OLD pickup. They bored and stroked it to 385 and it gets 535 HP and 540 ft.tq. And yes he did run it on a dyno. It is a street/strip truck and IT IS FAST!!! But him and his dad dumped a ton of dough into it. Alot more than $3k. As for a cam, a different buddy of mine advised me to stay away from edelbrock camshafts because they are weak, as in they are know to crack. I trust him because he is a mechanic in his dads shop and they are always building up one of their many cars. I hope things work out for you.

[jturkey69]

he never said his friend made 500 with 3 grand...just so you guys are aware...he said his buddy has 500hp.

now going to captjim's post...what kind of lift can be run on stock heads and springs? 210@ .050 on the intake..any other numbers that may work good..there arent many cams to pick from out of jegs/summit, so he may need some complete numbers and what to expect for idle/ cam range, and the fact that you cant rev these to the moon like his frinds Imp might be able to...lol. I get the vibe that the OP will feel alot of difference in just gear change, cam/carb/exhaust..prolly more then he will expect.

[jeffreyalman]

I have 2 455s and a 350 (cars in sig) not all that far off in years from you. My 88 was a dog when I got it compared to the 455s. I swapped the non-original qjet for an Edelbrock 600 and lost the cat and it feels like a 400 now. The 455s, even though breathing their own exhaust, are more than adequate (I have 3 land yachts) and a blast to drive. The 350 is now close. I would even call it peppy. Yes, I would.

[captjim]

Originally Posted by jturkey69

he never said his friend made 500 with 3 grand...just so you guys are aware...he said his buddy has 500hp.

now going to captjim's post...what kind of lift can be run on stock heads and springs? 210@ .050 on the intake..any other numbers that may work good..there arent many cams to pick from out of jegs/summit, so he may need some complete numbers and what to expect for idle/ cam range, and the fact that you cant rev these to the moon like his frinds Imp might be able to...lol. I get the vibe that the OP will feel alot of difference in just gear change, cam/carb/exhaust..prolly more then he will expect.

My 3920 lb Cutlass wagon ran 13.91 with a 210/216 cam in a 9 to 1 355 Olds engine and 3.42 gears. By comparison, my 4100 lb 440 magnum 10.25 to 1 410 geared Charger ran 14.0 waaaaaay back in the day. Technology advances. The general consensus is .500 lift, but I can't say for certain.

[Warhead]

Originally Posted by jeffreyalman

I have 2 455s and a 350 (cars in sig) not all that far off in years from you. My 88 was a dog when I got it compared to the 455s. I swapped the non-original qjet for an Edelbrock 600 and lost the cat and it feels like a 400 now. The 455s, even though breathing their own exhaust, are more than adequate (I have 3 land yachts) and a blast to drive. The 350 is now close. I would even call it peppy. Yes, I would.

If that was the case, your quadrajet had some issues.
I could never get a Carter AFB (now an Edelbrock-SAME carb) 600 to run within 3 tenths of a properly tuned quadrajet. I had the jet kit, etc,etc.

I sold ALL of my Carter/Edelbrock stuff.

If you can get an EXPERT to do an over the fender look at the q-jet, you will be happy you did. There are many things on it that will be detrimental to performance that lots of volume builders will not catch.

And your mileage will improve also.
MO
Jim

[Warhead]

Originally Posted by jturkey69

he never said his friend made 500 with 3 grand...just so you guys are aware...he said his buddy has 500hp.

now going to captjim's post...what kind of lift can be run on stock heads and springs? 210@ .050 on the intake..any other numbers that may work good..there arent many cams to pick from out of jegs/summit, so he may need some complete numbers and what to expect for idle/ cam range, and the fact that you cant rev these to the moon like his frinds Imp might be able to...lol. I get the vibe that the OP will feel alot of difference in just gear change, cam/carb/exhaust..prolly more then he will expect.

Lift is the big concern, not duration, to avoid coil bind, and any other binding.
I do not like big cams with stock springs.
How many miles are on your current cylinder heads?

When you consider that you will gain 25-30 cfm intake flow (just from cleaning all of the oil buildup from the backside of the valves), 30-40 hp from new guides (you do not want loose ones-they do not seat well) AND a 3 angle valve job, and the increased rpm potential from BETTER VALVESPRINGS, it really pays to do a set of heads BEFORE you do a camshaft swap.

Why put in a cam that gives you a 20 hp gain (with a loss of low speed torque), when you can get 50-70 HP gain from a performance valvejob???

Then stab in a cam, or do them at the same time.
You should do gears, and exhaust before it all.
My Opinion.
Jim

[70 cutlass s]

I ran stock springs with .500 lift before with no problem. It's not one or two things that you do to your that make it faster it's a combination of things. It's gears, exhaust, tranny, stall speed, how you build your engine cam size, head work, stoke, carb, intake, and the weight of the car are all part of a build. If you want to go faster it's all about time and money.

[85olds442]

Well you will not get to 500hp out of you 350, However you could get pretty close to an Honest 400hp. Providing you are willing to look for the Right Parts. Edelbrock RPM Intake manifold. Cam depends on three things, what kind of Compression Rear Gear and what Transmission and Converter. You Want to Make Power. #6 Olds small block head. Head Porting is a MUST!!! Compression no more than 10/1 on the Street. I like the Isky cams. ALOT od duration @.050 You will need at Least .230 @050 and over 500 lift to make some really good power. Forged pistons and get the bottem end balanced!!! I race at 5400ft in Colorado and my 350 olds runs mid 12's on the motor. That would be high 11's at sea level with a Hydralic Cam all Motor. Have beaten a Corvette Z06. He couldn't catch me but he was comming. I have a Total of 7000.00 invested in the car. If you want to see it run...youtube.com
Pueblo Motor Sports Park Oct 26-08 I come on at the 2.13 min and run a Cop car, I also run a Big Block Camaro Track Champion at the 4.33 min mark and race a Nova with a Mean 406 sbc and it took all he could to run me down at the end. I red lit but regardless you Can build a Really Fast 350 olds.