Hey guys looking for some opinions on a bone stock 1972 350 rocket. Good running low miles . I'm restoring the car and was considering trying to get some Xtra horses out of that engine with some bolt on equipment . Is it worth my while or do I have to get into the internals to get any kind of real increase in power?

 

Hi there, if you are looking for more power, it's going to be internal, I hear good things about E3 diamond fire plugs, giving a couple extra horses and slight emissions improvement, an outer job could be a set of headers, and any exhaust work, personally I plan to start with a new cam and headers

 

I ran a ton of 350 rockets in various cars and they are truly bullet proof . I was wondering about a set of w30 heads and aluminum intake but doubt I can get my hands on them . So id like to find something comparable to that equipment .then maybe add true dual exhaust .

 

I can't be sure about w30 heads but I know you can get a manifold through summit, and if you love sound I would look to the header system with good mufflers, it can free your motor and bring more power, if you get into it I know summit has most stuff that is a mild upgrade, but little things help, just depends on how much power you want, I personally can't use summit because I am in Canada and shipping is bad, if I could i would bore it 30 thou and go from there.

 

Stock 350 in 72 had pretty low compression, so bolt-ons are not going to make a huge difference. Gearing in the rear end will probaly give more results until you are ready to go deeper into the engine. That said, duals and a 4bbl (if now 2bbl) will make it sound and feel better even if not much real improvement as measured by a stopwatch.

 

What you could do is find a good running 73 350 and do a little work to get good useable compression. I ran a 73 350 shortblock with the 14 cc dished pistons , with 72 7A heads. Appx 9 to 1 compression with shim gaskets . For cam I ran a mild 260h comp cams with an edelbrock intake , 600 cfm carb and all the other stuff to match the combo . In my 72 through the mufflers I ran 13.86 in the 1/4 mile. Don't know how original you want to keep it but that set up was sweet simple dead reliable and it idled like stock with just a hint of a small cam.

 

W-30 heads are big block heads with larger combustion chambers than small block heads. Combine them with your deep dish pistons and your compression ratio would drop from ~8.1:1 to 7.4:1, which is NOT what you want to do for performance.

If you don't already have a 4bbl carb, get one. That and dual exhaust will help and are still useable if/when you do any upgrades to the internals of the engine.

As you can see from the 1972 350 factory ratings, 4bbl and duals are good for some noticeable power increases:

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

350 2-bbl dual 175 @ 4000 295 @ 2600
350 4-bbl dual 200 @ 4400 300 @ 3200


As hookem horns posted, better rear gears will make a HUGE difference. Back in the 80s I swapped the 2.56 gears for 3.08s on my bone stock '70 Supreme and it felt like I added 50 HP to the engine, then later I swapped in a 3.55 axle and it felt like another huge increase in power.

 

W30 heads are prob $3K so its prob not where you want to go. I'd agree that a gear change will give you the best bang for the buck. Duals & a switch to a 4 bbl if its currently a 2bbl.
If it is a 2 bbl, you can get a Performer but a Performer RPM would need a new cam to optimize & your compression won't allow too much cam.
With regard to a small block Performer, I've read that it doesn't flow any better than a cast iron intake so you'll save weight but won't make more power over a stock one.

 

I guess looking into the gearing is a viable option and it does have a factory four barrel .

 

1) Ignition - Performance Recurve

2) Tune carb, rebuild if nec (bogging, rich @ idle, etc)

3) If Auto Trans - Tune governor for 4500ish WOT auto shifts, maybe mild shift kit (just enough to firm up shifts a tad).

4) 3.08 - 3.50ish Rear End Gear.

Address the above & it'll feel like a different car. First 3 not a lot of money spent. Gears (& probably the requisite limited slip diff) a bit more pricey but good bang for buck if you have the common 2.56 peg legger.

5) Headers/Dual Exhaust (w/ X or H pipe?) & probably then a little carb recalibration (see #2 above) which could be held off until installation of exhaust components.

 

X3 with the gear swap. I would do a 3.23 or 3.42 depending on your taste of cruisng rpms. The biggest bang for the buck in off the line performance you will feel in the butt dyno is the rear end gears.

 

I'd first get the engine running as tip top as it can, Id do a compression test to see if the compression is good and even in all cylinders, you don't state how many miles are on it, if it's 90K or more you probably need a timing chain, carb rebuild and a total overhaul of the ignition for starters. After doing the basics assuming it's not a worn out oil burner then I'd worry about improvements.

 

I did a recent tune up on the motor it has 63000 original miles on it doesn't smoke idles nicely that's why I'd rather not tear into it just yet

 

https://classicoldsmobile.com/forums...um-intake.html

Performer available if you want to go that direction.

From my experience with my '70 Olds when I had it, nothing woke it up like going from a 2.73 to a 3.23 rear end.

 

Since it only has 63000 I'd add a non EGR Performer a 9834 Holley a good set of headers with a dual exhaust system and an HEI and call it good.