521 bbf
Thread Starter
|
New User
Joined: Nov 2020
Posts: 1
Likes: 0
521 bbf
Hi Im new here, and I have a question. I have a '77 460 stroked out to 521 and I need to know what spark plugs to use. I started with a Motorcraft SP-420 which becoming hard to get. What is the next plug you would recommend? It make about 625 HP.
Laughing Gas
Joined: Mar 2011
Posts: 811
Likes: 1
From: West Central Southern MN
Your build is more than what most have done. What compression is it running? My go to answer would be autolite 45’s, but you may be needing something better than the usual coppers.
Do you have an upgraded/updated ignition system?
Do you have an upgraded/updated ignition system?
Thread
Thread Starter
Forum
Replies
Last Post
Handegard
Big Block V8 - 385 Series (6.1/370, 7.0/429, 7.5/460)
17
Mar 23, 2012 09:51 AM
mean green2
Big Block V8 - 385 Series (6.1/370, 7.0/429, 7.5/460)
6
Oct 27, 2005 07:36 PM
dprasse
Big Block V8 - 385 Series (6.1/370, 7.0/429, 7.5/460)
4
Jul 24, 2001 06:38 PM
