I finally had time to get back to my truck. Been a very busy few weeks with moving and huge work project workload. Life ain't easy for a single dad.
74 gmc sierra, 454, th400, edelbrock 750cfm.
Anyway, I am still working my way through this truck and what previous owner did. I am not a gearhead for a living, but I am not afraid to do my own work or get dirty. I have done pretty much everything fuel and air related to date. I have been on the "spark" learning curve lately.
The truck did not have a timing tab at all, it has a mark on the balancer but there was no tab. That was a tight fit to get it in, but it's there now.
I pulled all the plugs to find tdc, using a compression test kit re-plumbed into a boost boost/vaccuum gauge. I manually turned the crankshaft clockwise and watched piston come up (boost), and then drop (vacuum). It took some time, but but TDC is established as "2" on the timing tab.
I decided to replace the distributor with the new cfr 65k hei I bought, and have installed. Have it installed, plug wires back in.
In the process of doing all of this, I pulled the msd6a that was installed. I do not think I need it on this truck.
Now I am wiring the HEI and I cannot find the install paper that came with the thing.
It has two connections, IGN and TAC.
For ignition, would it be better to come off the fuel pump relay I have installed instead of trying to tie into ignition circuit off the main panel block? It gets battery power, but only when key on. I tried looking this up and get conflicting information about using battery direct versus 12v switched. I could use some guidance on this.
Second, for TAC, I just use a ground right? Since removing the msd, I do not have a "TAC" source that I know of. or is the distributor providing TAC for my use on a gauge later?
...I wish I could find that paper that came with this thing...
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