Never had any experience with Jacobs, have always seen way more negative about them than positive though. I have had an MSD 6AL, it gave my little Ranger better throttle response and smoother idle.
I have a 77 with the vacume advance HEI. I just installed a CRANE HI-6 Ignition and in the cap coil. WOW, it made a very big differece in idle quality and low end power. It used to buck and give me fits if I tried to do very low r.p.m.s in a higher gear, not any more, it just pulls and drives smoother now. Its not going to give you a tire spinning axle snapping boost, if that is what you are after better look at nitrous. It will give you a smoother idle, better throttle response and if you get the timing retard control like I did, it will let you retard or advance your timing, or both, depending on how you set it up. That helps when you are pulling a heavy load or you get some bad gas, you can get rid of the knock.
Damn Knew I forgot something, the CRANE has built in rev controller, it has 2 rotary switches that you can set the rev limit in 100 r.p.m. incriments so you dont have to buy the right r.p.m. module or get one of the soft touch rev controllers. On the Vacume advance H.E.I. it also removes the stock ignition module and hooks to the stock magnetic pick up and the computer does all the work.
Depdog
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