Originally posted by Punkdog:
... What ign. system are you running ...
Duraspark I was the best performing ignition Ford had manufactured up until the introduction of the TFI ignition in 1983. It is the best ignition choice for “high performance” applications, but the very existence of Duraspark I has never been common knowledge because it was only installed in cars sold in California during the years 1977 – 1979. Its use was limited because the cost of manufacturing the ignition modules was several times the cost of manufacturing the Duraspark II modules. Duraspark II became the common ignition upgrade for older Ford V8s simply because folks weren’t aware there was a better alternative.
Duraspark ignition modules and coils are sold by SMP; p.n. LX203 for the Duraspark II module and p.n. FD476 for the Duraspark II coil. Duraspark I ignition modules are p.n. LX210 and the Duraspark I coils are p.n. FD477. The modules use different coils so caution must be taken to pair each module with the proper coil. Duraspark II wiring harnesses are available via the aftermarket (Painless Wiring p.n. 30812), they can be employed for Duraspark I applications by (1) swapping the position of the green and orange wires at the 4 pin module connector, (2) removing the flat blade “key tab” from the 4 pin module connector, (3) removal of the extended “tab” from the Duraspark I coil tower so that the Duraspark II coil connector can slip on, and (4) omitting the ballast resistor included with the wiring harness (the Duraspark I coil operates at full voltage). A good ignition wire set is also available from SMP (p.n. 69404); Pantera owners will appreciate the fact that this ignition wiring set has coil wires in 3 different lengths.
A Motorcraft breakerless distributor which is compatible with all North American Cleveland engines and the early (i.e. 1972 – 1978) Australian Cleveland engines can be sourced from any 1975 through 1982 351M, 400, or 460 cubic inch Ford V8. Cleveland engines built in Australia from 1979 – 1984 were equipped with Bosch distributors having a smaller diameter distributor shaft; thus the diameter of the distributor shaft bore inside the block is too small for the shaft of a Motorcraft distributor.
The distributor calibration for most applications should be 20° centrifugal advance which begins advancing at 1000 rpm and is all in by 2800 rpm plus 18° initial advance for 38° total advance. A Ford distributor should be equipped with a “sleeve and plate assembly” marked 10L or 10R in order to limit it to 20° centrifugal advance. A sleeve and plate assembly with a wider “notch” can be modified to reduce the width of the notch; the proper notch width for achieving 20° centrifugal advance is 0.410 inch.
Engines equipped with pop-up dome pistons may require more than 38° total advance to achieve full output, in those instances the distributor should be calibrated for 26° centrifugal advance which begins advancing at 1000 rpm and is all in by 3300 rpm plus 14° to 18° initial advance for 40° to 44° total advance. A Ford distributor should be equipped with a “sleeve and plate assembly” marked 13L or 13R in order to limit it to 26° centrifugal advance; or a sleeve and plate assembly with a different “notch” width can be modified to adjust the width of the notch; the proper notch width for achieving 26° centrifugal advance is 0.488 inch.
The distributor’s vacuum advance should be connected to the carburetor’s “ported” vacuum connection; a vacuum retard connection (if provided) should remain opened to atmosphere. There are businesses, such as Ignition Engineering of Anaheim California (714-334-9143), which can rebuild and recalibrate distributors for you. There are also a couple of guys on the internet, eBay, etc that sell rebuilt & re-curved Ford distributors. I buy the modules & coils as new old stock off eBay. Everything else, i.e. wiring harness, cap, rotor, wires; are also available on eBay. The distributor and the wire harness are the expensive parts. $600 sounds about right for a package.