1. Home
  2. Automotive Technologies
  3. 1974 Nova Upgrade

1974 Nova Upgrade

Hi,

We have a 1974 Nova and it's time to upgrade. We are the original owners and know it's history.

It has a 6-cyl 250, 3 speed transmission and drum brakes.

My upgrade plans include the following major steps

  1. Install V8 engine (283, 307, or 350, low octane with good MPG)
  2. Overhaul the front end
  3. Overhaul the transmission
  4. Overhaul the differential
  5. Install disk brakes on the front
  6. Replace front and rear springs

Please share with us your experience, parts lists, to-do lists, etc. for jobs you've done similar to this. We'd appreciate the information.

Also, we're located in San Diego so if you have shops or suppliers to recommend we'd appreciate that too.

Thanks, Charlie

Reply to
Charlie
Loading thread data ...

I would first want to do a serious frame inspection to be sure it can take any upgrades. They rot out at the tails just in front of the rear wheels.

The next step in my mind would be to find out what engine I was 'allowed' to put in it for street legal in California and build around that.

I would then want to be sure the transmission can take it and what rear end gears the larger engines came with stock. Lots of times the rear ratio is taller with a larger engine which you would want for mileage.

Sounds like fun,

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail > Hi,
Reply to
Mike Romain

I'm a Ford guy, so the specific are differant but the concepts are the same

  1. Keep the stock I6 engine and soup it up a bit. Light weight, good power, good economy. And, it would be differant. How many Nova's have you seen with a SBC? Pretty much all of them. How many with a nice looking I6? Pretty rare. Switch to side draft EFI, headers, a little chrome or polish. Maybe consider a turbo. That would be cool.
  2. I prefer poly bushings instead of rubber. I like the improved road feel, and willing to sacrifice the ride quality.
  3. Switch to T5. They're everywhere. Light weight, small package. Nice to drive. And an OD gear. Conversion kits are pretty common to switch to a hydraulic or cable pull clutch; which is a big improvement over the stock mechanical linkage.
  4. A nice set of stock type discs in the front will fell a little better than drums, and be inexpensive. Power is always better.
Reply to
.boB

Owned a nice 74 Nova Hatchback myself. 250-6 with a turbo 350 behind it. Added a few performance pieces from Clifford research, HEI ignition system. When I got done it was putting out far more HP than stock, and still got good mileage. Plus it was unique. Not a lot of 6s at the drag strip or on the streets. The 6 is a much smoother engine and easier to work on as well. For the front brakes you can convert it to discs real easy, You will need the spindles, rotors and calipers plus the master cylinder from a first generation Camaro (or aftermarket equivalents) They are a bolt on item. Springs from the same place.

Reply to
Steve W.

If this is to be driven on Sundays only, then do whatever...but 74 Novas with small-block-Chevy got around 12-14 mpg on highway, back then.

I've got two Chevy's, 82 Impala & 86 Caprice, that get around 20 mpg and 24 mpg, respectively on highway. The former has 267 c.i.d. with three speed Auto, and the latter 305 c.i.d., but the 305 has 4 Speed lockup transmission (700). Both of these use a carburetor, so, even if the computer fails, you still can get home....or they could both be converted to run on Carb only...but a loss in mpg.

formatting link

Imho, stick with a lockup TC-transmission, and some type of computer control of fuel delivery. Check out fuel economy before you jump:

formatting link
Also, in California, I think you have to meet emission standards for the motor...

I'm from the Midwest, but I plan on getting rid of these vehicles within next year, or so....if there was an interest....both can be driven to California, without breakdowns....I do watch this forum...rec.autos.tech...off/on.

Reply to
BigFoot

Well, a Ford guy contributed opinions so I guess I'll be the Mopar guy to contribute :-)

First off, items 2, 4, 5, and 6 are ESSENTIAL. Even for just restoring to "stock" engine power, you want good brakes and great suspension. GM midsize car suspensions from that era were kinda iffy at best, starting to head for "cushy personal luxury" ride instead of handling. Consider polygraphite suspension bushings, adding a larger front stabilizer bar and a rear stabilizer bar if not equipped. Springs- pick the stiffness you WANT, don't assume that stiffer is always better. If everything else is well-tuned, you can have a good ride AND decent handling.

If you're going to get rid of the straight six, I'd consider replacing both the engine and transmission with a modern multi-port EFI engine and

4-speed overdrive transmission. This should be particularly easy on a Chevy, and you have lots of engine choices ranging from a Vortec v6 (which will be a huge gain in both power and efficiency over your old 250), all the way up to an LT-1 or even LS-1 v8 with 3 times the power of your 250 (and would still get better mileage, too).
Reply to
Steve

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.