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Late Seventies cars

  
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Late Seventies cars

 
gtomustang gtomustang
Enthusiast | Posts: 457 | Joined: 06/09
Posted: 10/11/09
03:56 PM

Someone else posted somewhere around here, on why he didn't see more 70's tanks built up.  I can't find the original post, so I figured I'd just start anew.

B/c Detriot builds 5 yrs in advance, to have the time to test a product that needs to operate in a variety of climates, and not bankrupt them in warantee repairs, the early 70's cars were built to handle big blocks and racing.  Once the gas crisis hit in 1973, the cars downsized--a 1979 Monte Carlo is actually rated at a little over 3000lbs.  So if you want something different, and are thinking of doing something after the musclecar era, consider whether you want a big block, or a flyweight car with a stroker small block.

Before you get there, tho, as the editor of this mag found out...check your emissions laws first.  For example, if you can only outfit the 302 in your intended Ford with small-primary headers, don't bother stroking it to 347 cid.  Check into what the copcars came with that year (unless it was a 49 state setup in a California state, say) or considering putting in a 1988 or older 5.0 Liter H.O., with 2 of its four catalytic converters tucked up near the block.  that might help with undercarriage clearance, plus plenty of aftermarket heads with E.O. numbers, so you can stroke n' poke, and be able to exhaust it w/ BBK catcons, etc.  Typically, after the CC's is fair game, so you can put on the pipes you like, noise ordinances notwithstanding.

As Dodge found out, trucks didn't need catcons til late in the decade, and so made the faster car of that time--the Little Red Express truck.  Hey, why should only Chevy stepsides get built up?  Make a Warlock, or a Power Wagon...this was the era of spoilers and stripes. Why not a hot 360 or a Magnum...or a 3rd Gen Hemi?

Skip over the beater cars--finding weatherstripping, etc, can be real tough.  If you can find an off-brand old Grandpa car, with maybe only rubber and gaskets needing replacement...you could be dollars ahead.  But Mother Mopar and American Motors were going out of biz near the end of the Seventies, so build quality even on a low miler can be...um....well, American cars earned their rep during this time, ya know?

Unless you plan to use 80's tech, and make a torquer engine that runs at 2000 Rpm and redlines at 5000rpm (hey, ever run a TPI Chevy or a 5.0?), exhaust flow is everything.  Dump pipes, and a power adder, may be one choice--when you go to the track, switch to high octane, open the exhaust, and swap blower pulleys or hit the nitrous or whatever.

Or maybe you have to rely more on efficiency, and leave the revs to the Cosworth Vega.  Dry lubicant films, roller lifters and rockers, aluminum flywheels and pendulum cut or knifedged counterweights on the crank, et cetera.  But that emissions air pump probably won't give you the crankcase vacuum to keep thin piston rings stuck to the cylinder walls--and you have to keep cleaning the oil out of an evac system.  focus on making power at 3000Rpm, every time the trans shifts, the engine tends to fall to around this RPM.  It'll make the engine feel strong, b/c you never fall out of the power band.

Once you get the engine sorted out, then you can pick the rear gears: they all came in one form during this era--Bonneville lazy.  But then, the rear axle is probably weak--a GM 8.2" 10 bolt, a Ford 7.5", etc.  Consider a swap, and you may find you want to ditch the parallel leaf springs, too.  Consider overdrive transmissions--the extra gears may do more than give you gas mileage, then may keep the engine in the powerband, like 15 speed big rig transmissions keep that 3000rpm redline 14 liter diesel in its powerband.  
Just because you can't do it...doesn't mean its impossible