[roketengineer]

The factory tachometer on a 1970 Chevelle SS. I know it's driven by the coil (+) but I'm wondering if its 'square-wave'.

The reason I ask is because I'm doing an LS swap using a terminator xmax and I'm trying to figure out if I need to buy an adapter or I can hook the tach wire to the terminator x?

Any help would be great.

 

[GTO44]

More than likely you’ll need a tach adapter like this one for the factory tach to work.

https://www.summitracing.com/parts/msd-8920

 

[123pugsy]

On my 69, 5.3 swap with factory ECM, I had to add a resistor between tach wire and ground? to get it to work. Works fine.

 

[roketengineer]

More than likely you’ll need a tach adapter like this one for the factory tach to work.

https://www.summitracing.com/parts/msd-8920

gotcha, i think im gonna go with the dakota digital one. DD has always been very customer friendly to me.

https://www.summitracing.com/parts/dak-sgi-100bt

 

[hydro462]

I prefer the 1959 to 61 stock hi-performance distributor. The ones with the mechanical tach outlet are even more cool. A set of vintage Made in USA, Accel, 32 ounce points to trigger a Capacitive Discharge amp has worked well for me for decades.

 

[roketengineer]

I prefer the 1959 to 61 stock hi-performance distributor. The ones with the mechanical tach outlet are even more cool. A set of vintage Made in USA, Accel, 32 ounce points to trigger a Capacitive Discharge amp has worked well for me for decades.

we are talking about LS engines. They don't use distributors.