This is what i use on mine and my customers

https://www.ebay.com.au/itm/2746478...Stfqw8AIVEayWCh2VvQbKEAQYBSABEgK78PD_BwE

Its a tachometric relay . Ignition on no run 3-5 seconds of power to pump . So you can prime if fuel empty etc . Will shut off when no tacho signal .
Very reliable , but if it fails easily bypassed

Tex

Last edited by tex013; 05/04/21 05:23 PM.

New best ET 10.259@129.65 .
New best MPH 130.32
Finally fitted a solid cam,
stepped it up a bit more
3690lbs through the mufflers
New World block 3780lbs 10.278@130.80 . Wowser 10.253@130.24 footbraking from 1500rpm
Power by Tex's Automotive