A question for the other car people on the board....

[sld72382]

Lifelong mechanic and classic GM owner / enthusiast here. I can't believe I didn't find this thread earlier!

What most of the others here have said is correct- the car will be worth more the more original it is. Even so- don't hold your breath waiting for ANY late 70's Detroit sedan to become a serious collectible. There's still too many of them around, and their quality / performance deficit vs. their earlier counterparts make them less desirable in the marketplace, keeping values fairly low.

There are many things you can do make the car much more safe and enjoyable to drive, while keeping its original flavor. Swapping in an earlier 500 motor ( rebuilt of course ), painted in the same shade as your original engine, is a good start. Edelbrock makes an aluminum intake for these engines. You could have the runners extrude honed for better breathing. Paint it factory "GM Corporate Blue" and no one will know the difference. That aluminum intake will also shave some weight off the car's nose. A good 3-angle valve job with some bowl blending and mild porting will improve output without hurting driveability. Add a mild performance cam. The stock exhaust system on these cars is a joke. Replace the puny 2 1/4" single stock pipe with a 2 1/2" or 3" single along with a high-flow catlytic converter and a low-restriction yet quiet muffler like the Dynomax Super Turbo "Hemi" muffler.

In the handling department, some large aftermarket sway bars from Addco or Global West, along with some good-quality gas shocks like Bilstein or KYB will vastly improve the car's road manners, retaing a comfy ride without being quite so floaty. Thanks to GM's parts-bin engineering, many parts from other, lesser GM vehicles will fit these Cads. A new set of heavy-duty coil springs made for a 77-79 Chevy Caprice with the police / taxi package will help too. They even make a fast-ratio steering box for GM B-bodies to replace the sluggish factory unit.

Thanks for the tips!

FYI, this is what I was talking about. Man if I could float the finances I would buy this sight unseen: http://www.maaccc.com/node/101

[protege]

Even so- don't hold your breath waiting for ANY late 70's Detroit sedan to become a serious collectible. There's still too many of them around, and their quality / performance deficit vs. their earlier counterparts make them less desirable in the marketplace, keeping values fairly low.

Yep, the 1970s marked a serious decline in cars. They're still too many around, and what's left...after years of low values...isn't all that great. Not just Detroit iron either. Just about everybody got hit with emissions and safety regulations then. No wonder then that a 1975 MGB...with the single Stromberg carb and its lack of power, higher ride height--plus the rubber bumpers...is worth a fraction of what you'd pay for a '65 with none of that.

Then there are cars like the '58 Chevy...that will never have the same appeal that the 1955-57 ones do. A one-year body style that gets little attention now, and can usually be picked up for very little. A pity really, since you never see a '58 at shows. Everyone and their mom has the '55-57. Yet those cars are worth seriously more.

[wolfie]

A couple points from the purist viewpoint. First, GM didn't put 7.0 litre engines into 1970s Cadillacs - during that era, their V8s were still measured in cubic inches (although something in the 450 CI range would be equivalent to 7 litres). I cringe when I see metric measurements in articles about classic musclecars - I wish they'd write it the way it was done at the time, then put the metric equivalent in parentheses so people could compare it to what they know about current vehicles.

Next, definitely don't do anything that would keep you (or a subsequent owner) from changing it back to "numbers matching". Re-working the engine while using the original block is OK, as is swapping in another engine but keeping the original so it can be put back. Someone mentioned changing axle ratios - if you can swap the ring and pinion in the original housing, do it. If you need to swap the entire axle, keep the original - that's one of the numbers that gets matched.

I agree that it's a low power output. 2 types of engine that have a reputation for low power densities are heavy trucks (sacrifice power density for reliability - million mile engines are relatively common) and aircraft (have to keep the RPMs down so the propeller tips don't "bust the mach"). A fairly common truck engine is the 550 HP C-15 CAT - scaling that to your displacement would yield around 256 horses. Also, a fairly common engine for light aircraft is the O-360 Lycoming ("O" refers to horizontally opposed, contrast with "R" for radial, and the number is how many cubic inches) at around 180 horsepower. The IO-360 (fuel injected version of the same) is around 200 horses. These would be around 5.7 litres.

[ADeMartino]

A couple points from the purist viewpoint. First, GM didn't put 7.0 litre engines into 1970s Cadillacs - during that era, their V8s were still measured in cubic inches (although something in the 450 CI range would be equivalent to 7 litres). I cringe when I see metric measurements in articles about classic musclecars - I wish they'd write it the way it was done at the time, then put the metric equivalent in parentheses so people could compare it to what they know about current vehicles.

I agree, but we have to evolve with the times. Personally, I'd rather refer to my engine as a '289' instead of as a '4.7'. But '289' doesn't mean anything to a generation that grew up with metricspeak. Unfortunately, metricspeak IS the default terminology today, which is why the magazines and so on often use the metric figures - so that modern readers can compare what THEY know to the 'old school'. I also agree that the metric designation could be put in parentheses or something somewhere, but I guess it's an awful lot of work to type those few extra characters in a magazine article.

Besides, the metric designations WERE sometimes used in the old days. NASCAR once had a 7.0 liter limit on engine displacement. Trans-Am (the race for which the car is named) originally limited engine displacement to 5.0 liters - which is precisely why the original Z/28 Camaros had that oddball (and SWEET!) 302, and Ford was playing with Tunnel-Port 302s before finally rolling out the Boss.

Incidentally, for those interested, the conversion is 61 cubic inches (+/- 3) = one liter.. So, a '7.0' is a 427, but so are 425s, 426s, 428s, and 429s. The Chrysler 440 was a 7.2, the GM 454 and 455 V8s are 7.4s, the Ford 460 is a 7.5, and the Caddy 500 is an 8.2. That's right, kids. Once upon a time, GIANTS roamed this land in large numbers.

[Chromatix]

You might find this amusing:

The 1974 240 series retained the B20A 4-cylinder engine from the 140 Series in certain markets, with the new B21A engine available as an option on the 240 DL models. The new B21 engine was a 2127cc, 4-cylinder unit, which had a cast-iron block, a five-bearing crankshaft, and a belt-driven overhead camshaft. This engine produced 97 bhp (72 kW) for the B21A carburettor 242DL, 244DL and 245DL, and 123 bhp (92 kW) for the B21E fuel-injected 244GL. All 240s were fuel-injected in the US market; the carbureted B20 and B21 engines were not available due to emissions regulations.

The 2.127L displacement converts to 130 cu in. That's the magnitude of the difference between American and European engines in the 1970s.