1973 454 upgrades for mileage/drivability

[curtis73]

I just got myself a 1973 Impala Wagon with a 454/400 combo. The car was a barn special with exactly 58,163 miles on it. Some upgrades are planned and just for the sake of background I'm a pretty accomplished wrencher with very little chevy experience except LT1.

First to go will be the manifolds and 2-into-1 exhaust and very crimped 2" single exhuast. In its place will go 1-3/4" headers, dual 2", and some quiet-ish mufflers. Maybe a crossover and resonators to help keep it quiet, too. Somewhere along the lines an Edelbrock intake and (I have to research it first) a head swap. Maybe the ones on there are fine for the stock cam, but maybe there are some better choices like the 049s or 771s.

One of the first things I want to do (and the reason for this post) is to try to maximize my mileage with some ignition upgrades. Don't laugh at me. I'm actually quite happy with the 14 mpgs I'm getting, but if I can make it 16 I'll save myself a touch at the pump. Why waste, especially when many of the mileage goodies will help cold starts and HP a little as well. So, what would you all suggest for ignition. The way I see it, there are the following options:

1) Upgrade to a rebuilt junkyard HEI
2) Buy an aftermarket new HEI
3) Buy an aftermarket Points-to-magnetic/hall trigger like Pertronix and get a better coil
4) Any of the above with a Jacobs, Mallory, or MSD ign box added on.

Any other thoughts, ideas or quips?

PS. the target here is just a plain old daily driver street car that might tow 4000-5000 lbs very infrequently. I might do a mild roller cam in the future, and (like I said) its possible that better factory iron heads, air-gap-type intake, headers may all be in the near future. The factory HP rating was 215, so I might shoot for 300, but envision the torque still peaking really low, like below 2500. Its a heavy car, so I doubt a "performance" spark curve will help especially when towing.

[bigdaveangell]

If your going at all toward performance see if you can find some vortec heads. A big part of your power is in the heads. Aftermarket ignition will probably help a little. MSD and Jacobs are both a good choice. I havent ever used a mallory igniton but I havent heard anything bad about them.