V6 Mechanical Advance Electronic Ign Distributor?

[Garrett Ellison]

We've done a few magnum changeovers and have some used 318 and 360 LA roller cams, so it's a free upgrade that also allows us to use an LA cover with a mechanical fuel pump. The 318 roller gives .460 lift so it works with the magnum rockers for .461 lift, the 360 gives a .437 intake .445 exhaust. Still within the capability of stock springs. Stock magnum cams are generally in the .410 inch lift range, so the LA cams make enough of a difference to make it worth the effort. The main reason we started doing it is because we found upon inspection during teardown and freshening up that all of the factory cams we have seen so far from the used magnum engines have flaking on the lobes, while the earlier LA cams seem to be of better quality. Here's the link to the garage here on sight if you haven't checked it out, spec's are in the Dyno. 71,000 mile car that sat at a Carter Caterpillar from 1982 to 2013 waiting on a front clip.
1971 318 Twister

 

[rdunnam]

We've done a few magnum changeovers and have some used 318 and 360 LA roller cams, so it's a free upgrade that also allows us to use an LA cover with a mechanical fuel pump. The 318 roller gives .460 lift so it works with the magnum rockers for .461 lift, the 360 gives a .437 intake .445 exhaust. Still within the capability of stock springs. Stock magnum cams are generally in the .410 inch lift range, so the LA cams make enough of a difference to make it worth the effort. The main reason we started doing it is because we found upon inspection during teardown and freshening up that all of the factory cams we have seen so far from the used magnum engines have flaking on the lobes, while the earlier LA cams seem to be of better quality. Here's the link to the garage here on sight if you haven't checked it out, spec's are in the Dyno. 71,000 mile car that sat at a Carter Caterpillar from 1982 to 2013 waiting on a front clip.
1971 318 Twister

I take it that the LA cam lobe profile is little or no difference than magnum. Or is it just the 88-89 pre mag cams (roller)you’re referring to?

 

[Garrett Ellison]

Correct, the durations are nearly identical save for some minor differences in LSA (I “think“ in the 114-117 area) and duration. Oftentimes the magnum cams are in the .370-.410 range at the 1.6:1 rocker ratio, so any extra lift at all makes enough difference to feel.