HEI Plug Wires

[mattfranklin]

I know it's an old post, but I just wanted to say that I really appreciate the detailed documentation in this that included the wire lengths, locations, and part numbers. It helps a lot. Thanks, JimH!

Originally Posted by JimH2828

To assist others down the road, I figured I would add to this older post. I just replaced my incorrect over the valve cover spark plug wires with correct under the exhaust manifold wires on my 70 350 4x4 with HEI.

I used ACDelco spark plug wire set 9088S. Black, 8mm, 90 degree boots. I measured the lengths and ran them to the following cylinder plugs - 1: 48”, 2: 56”, 3: 56” 4: 44”, 5: 29” 6: 29”, 7: 22”, 8: 27”.

Note 1: I ran plug wires 1\3 through the driver side engine mount and 2\4 through the passenger side engine mount. I couldn't find any drawings that show this, but I have seen some other forum guys do it and with the above lengths I needed to. A little grease and the boots slipped through easier than I thought they would.

Note 2: 1\3 and 2\4 use the duel wire retainer by the heat shield but 5\7 and 6\8 do not.....see drawings. With these lengths 5\7 could use a duel wire retainer by the heat shield but 6\8 couldn't........I do have them installed there thinking 4x duel retainers were used, but it looks like only 2 were correct.

Note 3: 1\3 and 2\4 also use the duel wire clips that mount to oil pan bolts on each side....hard to determine from drawings, but I have seen other guys use them and I think they help.

Note 4: Based on my install, wires 2\4 are a couple inches longer than needed, but I was able to get a good setup adjusting at the retainers.

Attachment 1479528 Attachment 1479529

Hope this helps somebody,
Jim