Hi all,
I'm new to the site, and have a question on a cam upgrade, I'm more less looking for someone to tell me what my best choice would be on what cam, lifter, push rod and valve springs to run. I have a 1972 cutlass s, 350/350 completely stock 47,000 mile car, power brake non a/c car. Currently it is a 2bbl single exhaust car, I found a 4bbl cast iron non egr intake and rochester quadrajet carb that I bought reasonable, I also have headman headers and 2-1/4 dual exhaust kit with 2 chamber flowmaster mufflers I'm putting on, I'm looking for a good cam to run with the intake/carb and exhuast setup I'm putting on, something with a noticeable lump at idle, but still decent street drivability, I plan on keeping the trans and rear end all stock since I do drive the car quite often on road trips to shows. Any advice would be great

 

Ask Mark cutlassefi. Oh welcome to the site.

 

Unfortunately your 350 has around 8 to 1 compression, . Talk to Cutlassefi, he does custom grinds for low compression Olds V8's.

 

The best you can do is about a 214/214.050 on a 108lsa.

I'll stick with a this recommendation.

 

The cam recommendations by Mark are good ones. If you are determined to go into the engine just to put band aids on it then take his advice.


IMO a better option would be to just leave the engine alone for now & find more performance through your exhaust upgrades & put a more useable gear in the rear end (suggest a 3.23 & add posi if it does not have it). Save the engine upgrades for when you can afford to do it once & do it right.


Just my 2 cents but best of luck with what ever you choose.

 

Maybe I should rephrase my question a bit, maybe lumpy idle wasn't the best term, I guess I was wondering if there is a cam that will work better than stock cam and be noticable at idle, the engine only has 47,000 original miles, I thought if there was a better cam than the stock cam now would be the time to replace it since I will have the motor partially apart. My thought was to do a timing chain and gears when I do intake and headers. I'm.not really looking to go radical, or to build a new motor

 

My toy

 

The factory cam is very mild, so yes, you can easily go with a better performing cam. You need to keep in mind that the engine has very low compression so it is easy to overcam it and have poor results, so you will need to stay far away form anything with a "lumpy" idle. An RV type cam with around 204º duration @ .050" lift will be an improvement without sacrificing driveability.

 

I ran the 204/214 Performer cam in a 8 to 1 350 was OK but Mark's would be better, much tighter LSA which will also make it "lumpier" at idle. Also spend the money on the Cloyes billet timing set, supposed to be more accurate but degreeing would be best.

 

Welcome to the site. Very nice looking ride!
Couple things to consider:
1- Consider giving pause to cracking open an original 47k motor if everything is mechanically sound. Timing chain replacements aren't usually a sub 50k mile fix.
2- If you're looking to give your 72 a more aggressive or noticeable muscle car sound consider starting with something less invasive like a quality exhaust system. Full length headers->xpipe-> 2.5" super 44s, 40s, etc will give your car a much more aggressive sound, improve performance AND you can check that off the list of upgrades should you decide to go with a more substantial build down the road.

Good luck.

 

I am betting being that age it needs gaskets anyways. The timing gear has a bad habit of falling apart and going in the oil pump pick up, no matter the mileage. The mid 70's motors don't seem to have that problem as often. He can upgrade to a 2 piece rubber main seal while he is at it. A step up to the 4 bbl, Mark's cam, dual exhaust and a slight gear bump to 3.08-3.23 would be massive. Nice car, there is a 70 local with a black vinyl roof with similar mileage and a holiday vs your fastback for $14,000, would like it in my driveway.

 

X3 on the gear swap. if the engine runs good i wouldnt touch it besides going to maybe a 4 barrel intake and carb . I would add full length headers and a good free flowing exhaust. Dont buy flowmasters they are flow junk lol. Hooker aerochamber mufflers are much better.

Personally i think a 3.42 is perfect for the street . A good tune up. re curve the dist , bump the timing up will all make a world of diffrence.

 

Hooker Aerochamber's are quiet at idle but very noticeable when you step on it. I have no drone with a X pipe and 2.5" dual exhaust with Sanderson shorty headers.

 

That is one clean, sweet looking Cutlass! I wouldn't touch it! Not sure you would get any improvement, or much, from a 4bbl setup.

The Jim Hand Muffler Test still is valid data, and the baseline for all performance muffler tests:

http://www.pontiacstreetperformance....p/exhaust.html

Small tube headers if you want, 2.5" exhaust, X pipe, and Dynomax Super Turbo mufflers are very hard to beat.

I ran the AP Xelerators for one build, really liked those, but they do score slightly lower than the Dynomax.

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It was worth, what 15 hp and a handful of torque on a stock motor? He should see a slight mileage gain over the stock 2GC as well, if it came off a similar 350.

 

Thanks for all the comments on the car guys, it is my dream car. Growing up my older brother had a 72 cutlass s that I always loved, he sold it before I could drive, let alone afford it. The car pictured is a 72 s and I am the second owner, original owner bought it new in October 1972 at badger olds in Oshkosh wi, I went to high school with the owners grand daughter 20 years ago, when grandma passed 2 years ago out of the blue the grand daughter looked me up after all those years and asked if I was still into cars, and now its mine

 

 

According to Oldsmobile, a 4bbl is worth 20 more horsepower with a single exhaust system and 25 horsepower with a dual exhaust system. Remember that in '72 all 350s had the same compression, camshaft, heads, etc.; the only difference was carb/intake/exhaust.

A quick summary of the specs for the 1972 350 engine taken from the Owners Manual:

350 2-bbl single Exhaust 160 HP @ 4000 RPM 275 FT-LBS @ 2400 RPM
350 4-bbl single Exhaust 180 HP @ 4000 RPM 275 FT-LBS @ 2800 RPM

350 2-bbl dual Exhaust 175 HP @ 4000 RPM 295 FT-LBS @ 2600 RPM
350 4-bbl dual Exhaust 200 HP @ 4400 RPM 300 FT-LBS @ 3200 RPM

 

What's in these cars for a rear end? I know its a 10 bolt, but doing some reading online I see some 8.2 10 bolt, some 7.5 10 bolt, some c-clip, some are bolt in Axel. I know it is a 10 bolt open in it, but what was the common size and Axel mount style in these cars?

 

72s have 8.5s, bolt in 'BOP' axles. They are good rears, and prepared properly can handle decent power, I would say 600x600 on slicks, if not a little more.

I was shy of replacing the ends and welding the tubes, think I have like $1400 in it, and I have no worries about it lasting. Can check my build thread on what all was done.

Quick recap: Cleaned housing, checked for straightness, TruTrak, 342s, Moser axles, billet caps, cap studs, 1350 yoke, and a rear cover/cap support.

Also did a Right Stuff Detailing rear disc conversion with parking brake. That was an additional $450.

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With 3:23 or 3:42 gears would it still be a decent driver on the highway? I do like to drive it to shows, and most of them I went to last year were 60-70 miles from home and all interstate driving 70-75 mph, I honestly don't mind throwing a little money at it for performance fun, and it sounds like headers, 4bbl and gears are the way to go, I just want to get the most for my money

 

You can calculate that for yourself using any of the hundreds of RPM calculators online. Just use the desired gear ratio, your estimated speed & your tire height to calculate RPM.


If you are still running 14" rims the largest/tallest tire you can buy is a 225 70 14 which is 26.4" tall. Assuming your 70 mph cruise RPM you will be turning 2955 rpm with the 3.23 gears & 3129 rpm with the 3.42s. 3.08 gears will drop your cruise rpm to 2818.


If you don't like those cruise RPMs then start looking for 15" rims on which to mount taller tires or start shopping for an OD trans.

 

Go with 3.08 gears.

 

Choosing the right rear ratio cant be done without finalizing a tire height.


It would be unwise to recommend a 3.08 gear only to find out that the OP plans on running a 28" tall tire. That combo will kill the off the line performance of a 350 2bbl.


If he plans to stay with 14" rims then the 3.08 makes sense if highway driving is a priority. If off the line poke is more important the 3.42 is a better choice. To me the 3.23 is the compromise winner.

 

Myself, I hated running at that rpm on the highway when my first 2004R died. He does have to finalize what size tire he will run before picking gears, so any suggestions will be mute until he does.

 

For tires I am running 235 60 14

 

With that 25" tall tire, definitely go with 3.08 gears. I run around 1850 rpm at 60 mph with a 2004R overdrive with the converter locked and running the same 235/60R14 tires.

 

From a performance standpoint, small blocks like gear, usually in the 373-411 range. Anything less than 373 is a compromise.

Obviously, that type of gear isn't going to be highway friendly, unless you have an overdrive.

I wouldn't even consider anything less than a 323. I did the Power Tour with 342s and it was manageable. If I kept it below 60-65, I was fine, anything over 70 and the mpg dropped sharply.

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For his combo, a stock 2004R with a good shift kit would do fine then run 3.42 or 3.73 gears. His 350 is 8 to 1, it will run out of breath fairly quick, 3.73 is plenty but OD is necessary with his tire size. My Dakota has the stupid feature of locking out OD in our frigid winters, with 3.92 gears even with 31" tall tires, 3000 rpm gets old fast.

 

I decided to do the gear change and add a posi, my plan is to go with 3:23 gears, I have the car in winter storage till the middle of March so I won't get a chance to pull it apart till then, does anyone know what spline Axel came in those cars? From what I have seen I need to know if it is 28 or 30 spline before I can order a posi. I may also do a disc brake conversion in the back

 

Should be a 28 spline.

 

For $200-250, you can replace them with new, and that's cheap insurance against failure.

Heat cycling, bearing failure, and any type of load/impact could have compromised the axles. It makes sense to replace them.

If you're planning on a disc conversion, most kits have a requirement that the flange be less than a certain diameter. Look at the kits you are interested in, and make sure you get the flanges cut if they aren't small enough.

I used the Right Stuff Detailing kit AFXRD01, has a parking brake, and is $395 shipped:

http://www.summitracing.com/parts/rs.../model/cutlass

Axles flange diameter is listed as 3.125" max, but I've found it's better to go slightly smaller, since many flanges have a small step on them.

I ordered my Axles directly from Moser, and asked they cut the flanges. Think they were like $285 for the pair to my door.

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