Posted By: Robbins
318 302 heads - 11/18/14 11:48 PM
Is it necessary to plug the holes under exhaust ports they have a ton of miles on them and they look to be plugged up with carbon? Customer is putting headers on......truck application. Thanks in advance Moparts.
Posted By: burdar
Re: 318 302 heads - 11/18/14 11:57 PM
You can easily run a tap into the holes and plug them with allen head set screws.
Posted By: Robbins
Re: 318 302 heads - 11/19/14 12:29 AM
Ya...done that with some 86 360 heads with the same style headers.....but I thought that I seen where someone got away with not doing it. Anyways thanks for the quick reply.
Posted By: Robbins
Re: 318 302 heads - 11/19/14 12:59 AM
Does anybody know what size tap and plugs you need
for this project?
Posted By: RapidRobert
Re: 318 302 heads - 11/19/14 01:07 AM
13/64 and 1/4-20 iirc. EDIT 13/64 for the drill bit and 1/4-20 for the tap and plug. To plug it a 1/4 coarse thread stud with the female recess for an allen wrench to screw it in works good. Just pick the right length
Posted By: dogdays
Re: 318 302 heads - 11/19/14 06:26 PM
My 302s I did that, broke a Greenlee tap off in one hole, so be careful. Plugged all the other holes with some short bolts I had found in a parts drawer, plugged the "tap hole" with JB Weld.
10,000 miles later all are still plugged.
BTW, I used a rotary cutoff wheel to take off the bolt heads. May be cheaper than setscrews.
R.