engine rpm and sparkplug gap

[dfillhard]

i have a 74 bronco with a bone stock 302 motor with 2 bbl carb. i changed the points out for a petronics igition. i then took it to a mechanic how worked on the timing and carb setting it up for me. it ran great for about 3 years. im now doing my own tune up... i live in san diego cal. what type of spark plug should i be using also what gap, the original under hood sticker says gap at 36 the manual i have says gap at 44....? also what should my rpms be at idle with engine hot? the mechanic who did the work for me has retired and i cannot locate him to pick his brain, but he did nopte on my reciept that the timing is at 10 degrees btdc vac diconnected and rebuilt carb and rejetted carb. any help on this would be greatly appreciated thankyou...

 

[Seabronc]

If it is not a stock ignition, do what the manual for the ignition system says. With my MSD ignition, I gap at 40. Idle RPM depends on the transmission, Manual around 450 to 500; automatic is set to around 650 when in gear which comes out to around 1100 in neutral. For a automatic, it is called the curb idle adjustment, which is never set until all other tune up items are set right.

For the automatic, set it to the lowest setting that the engine will run at without stalling when in gear and the breaks on and then add about 50 RPM. That procedure take a bit of playing around but once set properly it will run just fine.

Good luck,

>-

 

[aqua_wonder]

I have a 72 with the Crane Cam module. I used regular motorcraft plugs and gaped them at 40. Manual transmission idle is set to 650-700.

 

[S_bolt19]

I don't remember what non EFI gaps should be, but I would definatly stay away from the high end plugs. I always had the best luck, with my 302, with the $0.99 Autolite plugs, better than Splitfire or any of the Platinum type plugs.