Timing a 4.3?

[Browning]

91 Chevy 1500 4.3 Its a buddies truck, been overheating like crazy. Ive eliminated a few things, now Im moving towards it being a tad out of time. Whats the best way, w/o a light to check the timing? Also what about setting it, and can somebody explain the bypass wire under the carpet please?

[Dave1647545494]

you can set timing without a light by hooking a vacum gage up to the manifold and advancing the timing untill you get the highest reading on the gage then you want to back it off so the gage reads an inch or two lower than the highest reading.

 

hth

[Guest TGrant]

I think the "bypass" wire you are talking about is what you unplug to put the truck into base timing. It should be a tan/black wire with a sput connector that you need to unplug to put the truck into base timing and then you can start setting the timing. Once you are done setting timing be sure to plug this wire back together.