cadillacdeville
05-24-06, 10:33 PM
I am converting a 1969 472 to HEI do I need to change the gap on the plugs they are new bosch plugs set a .035 gap which is factory but thats with points type distributor the 425 its replacing is HEI with plugs set at.060 any info is much appreciated
caddydaddy
05-25-06, 07:28 AM
The HEI is a much higher power ignition system, which provides a better spark. So to take full advantage of that, run the 0.060. I use the same set up on my 1972 472.
cadillacdeville
05-25-06, 09:36 PM
thats what I'll do. thank you for the info.:thumbsup:
Night Wolf
05-26-06, 02:56 PM
yup, I'll second the .060" :)
Speaking of spark plugs, I would like to go colder plugs on my '69 Fleetwood Brougham. Just one step down (colder). What would the part number or code be for that? The orginal part number for the plugs recommended is R-44-N, but I doubt that code is still used at auto part stores.