Hi guys, does anyone know what the total timing on a 1983 LG4 would be? I don't have a timing tape or dial back light handy to check. With the EST wire disconnected the factory spec is 6 BTDC. It looks like idling with the EST reconnected the car idles in the 15-20BTDC range (just eyeing it). I thought I remembered the LG4 had 30 total timing and the L69 had 36? Is this correct?

We all know a SBC runs best with about 36° of "total" timing. Doesn't matter what the emissions sticker says, or how they crippled it to make it help out their CAFE number, or any of that other stuff that has NOTHING WHATSOEVER to do with getting it to run its best, or even with getting it to run RIGHT. That one "number" has to serve too many masters.

Say for the sake of argument though, that it was 40°. What difference would that make to whatever it is you're doing? In other words, where are you going with this, in terms of trying to accomplish something?

I don't want to over advance at the top end. Some of the emissions crippled engines that were computer controlled had restricted timing at idle and off idle but still made 36 total timing. If that is the case with this computer I am not going to bump the base timing up 10 degrees more than stock!

Also it is entirely not true that 36 total is always best. This only holds true for the old extremely inefficient open chamber SBC heads. Closed and fast burn style heads will make peak hp with sometimes as low as 30 degrees WOT.