I just picked up a 95 Jimmy 4.3, and I did a head job on it. I removed the distributor, and lost my marks.. so Im trying to reinstall the distributor. Im almost possitive I have Top Dead center, but I just cant get the dist. to line up so the cap fits on. There is a little pinon the bottom where it mounts that seems to be right in my way of where I think I need to be with the distributor.. Anyone tell me exactly how to get this distributor mounted in correctly? I have searched the internet, but only found very general guids.. I need more specific info. Please help.. Im sooo close to getting this truck running.

 

1st make sure you are at top dead center of compression stroke then line up rotor with #1 plug should drop right in. let me know if this does not work.

 

You won't be able to line it up exactly on the #1 plug location on the cap because of the helix on the gears. It will have to be rotated down in. I try to always spin it over to TDC compression on #1 (both valves closed), mark the distributor with a paint marker for the location of #1 as well as the final position of the rotor after pulling the distributor clear of the cam gear.

For your purpose, you'll have to do it by trial and error to make sure that you are not a tooth off. Having never pulled the distributor off of a 4.3L, I do not know how far to tell you that the rotor will swing. And since it has been a real long time since pulling a distributor, I couldn't even say which direction it'll turn.

Another thing to note is that the oil pump drive must be lined up properly as well or you won't be able to fully seat the distributor.