L71 Timing tab

[Tom R.]

I'm pretty sure the timing tab isn't correct on my car. I believe mine should be angled on the top side but mine is straight. There are pictures of mostly every one available in the Zip Catalog. Mine looks to be the one shown for a 66, 425 hp. Anyway, is the spacing the same between the tick marks for all the tabs? Mine has 8 marks either way with the 5th mark being longer. I'm assuming that mark is the 5 mark with every other being a 1. Meaning I can read mine from 0 to 8 each way. Or is it the 10 mark with the others being 2s, thus reading 0 to 16?

[Larry S.]

Re: L71 Timing tab

Tom. The fifth (longer) mark is 10 Deg. Each mark is 2 Deg. either advanced or retarded from Top Dead Center (0 Deg ). With your vac advance disconnected and the vac line plugged, idle at about 900 rpm, you should do an initial setting of say, 10 Deg. advanced and that will give you a basic start. I have a 66 BB with the 10-12 degrees as a basic timing.

[Grant W.]

Re: L71 Timing tab

Hi Tom
As far as I know the 435hp cars used the timing tab that is pointed. But again what year is your car.
There were three versions of the BB timing cover 65 to 70. The first two lacked locating holes for engine mounted dowel pins at the lower outside edges while the late version of the timing cover had dowel pin holes. The earliest version of the cover without dowel pin holes included a weld nut to secure the forward lip of the oil pan to the bottom center of the timing cover. All three versions had the timing tab welded to the cover.

If you have the square tab then most likely this one is the middle version of the cover without dowel pin holes and without the weld nut. It's timing tab is located to accommodate engines with 7-inch harmonic balancers most likely from the '67L-68 era.

So if you have a 67 or 68 435hp car it should be pointed tab and no dowel pin hole.
If you have an early 69 built in 68 then it may have the same timing cover as the 67 and 68.
If you have a Jan built 69 then its with the dowel pin timing tab cover.
Hope this helps.
Grant

[Tom R.]

Re: L71 Timing tab

Mine is an early (December) 67, making it the wrong one with square ends from what you're saying. Knowing that the longer mark is 10 helps as I was assuming it to be 5.